Zinc Containing Complex and Condensation Reaction Catalysts, Methods for Preparing the Catalysts, and Compositions Containing the Catalysts

ABSTRACT

A composition is capable of curing via condensation reaction. The composition uses a new condensation reaction catalyst. The new condensation reaction catalyst is used to replace conventional tin catalysts. The composition can react to form a gum, gel, rubber, or resin.

Tin compounds are useful as catalysts for the condensation cure of manypolyorganosiloxane compositions, including adhesives, sealants, and lowpermeability products such as those useful in insulating glassapplications, coatings, and silicone elastomer latices. Organotincompounds for condensation reaction catalysis are those where thevalence of the tin is either +4 or +2, i.e., Tin (IV) compounds or Tin(II) compounds. Examples of tin (IV) compounds include stannic salts ofcarboxylic acids such as dibutyl tin dilaurate, dimethyl tin dilaurate,di-(n-butyl)tin bis-ketonate, dibutyl tin diacetate, dibutyl tinmaleate, dibutyl tin diacetylacetonate, dibutyl tin dimethoxide,carbomethoxyphenyl tin tris-uberate, dibutyl tin dioctanoate, dibutyltin diformate, isobutyl tin triceroate, dimethyl tin dibutyrate,dimethyl tin di-neodeconoate, dibutyl tin di-neodeconoate, triethyl tintartrate, dibutyl tin dibenzoate, butyltintri-2-ethylhexanoate, dioctyltin diacetate, tin octylate, tin oleate, tin butyrate, tin naphthenate,dimethyl tin dichloride, a combination thereof, and/or a partialhydrolysis product thereof. Tin (IV) compounds are known in the art andare commercially available, such as Metatin® 740 and Fascat® 4202 fromAcima Specialty Chemicals of Switzerland, Europe, which is a businessunit of The Dow Chemical Company. Examples of tin (II) compounds includetin (II) salts of organic carboxylic acids such as tin (II) diacetate,tin (II) dioctanoate, tin (II) diethylhexanoate, tin (II) dilaurate,stannous salts of carboxylic acids such as stannous octoate, stannousoleate, stannous acetate, stannous laurate, stannous stearate, stannousnaphthanate, stannous hexanoate, stannous succinate, stannous caprylate,and a combination thereof.

REACH (Registration, Evaluation, Authorization and Restriction ofChemical) is European Union legislation aimed to help protect humanhealth and the environment and to improve capabilities andcompetitiveness through the chemical industry. Due to this legislation,tin based catalysts, which are used in many condensation reactioncurable polyorganosiloxane products such as sealants and coatings, areto be phased out. Therefore, there is an industry need to replaceconventional tin catalysts in condensation reaction curablecompositions.

BRIEF SUMMARY OF THE INVENTION

A reaction product of ingredients comprising a zinc precursor (Znprecursor) and a ligand, and methods for preparation of the reactionproduct are disclosed. A composition, which is capable of forming aproduct via condensation reaction, comprises the reaction product and asilicon containing base polymer.

DETAILED DESCRIPTION OF THE INVENTION

All amounts, ratios, and percentages are by weight unless otherwiseindicated. The amounts of all ingredients in a composition total 100% byweight. The Brief Summary of the Invention and the Abstract are herebyincorporated by reference. The articles ‘a’, ‘an’, and ‘the’ each referto one or more, unless otherwise indicated by the context ofspecification. The disclosure of ranges includes the range itself andalso anything subsumed therein, as well as endpoints. For example,disclosure of a range of 2.0 to 4.0 includes not only the range of 2.0to 4.0, but also 2.1, 2.3, 3.4, 3.5, and 4.0 individually, as well asany other number subsumed in the range. Furthermore, disclosure of arange of, for example, 2.0 to 4.0 includes the subsets of, for example,2.1 to 3.5, 2.3 to 3.4, 2.6 to 3.7, and 3.8 to 4.0, as well as any othersubset subsumed in the range. Similarly, the disclosure of Markushgroups includes the entire group and also any individual members andsubgroups subsumed therein. For example, disclosure of the Markush groupa hydrogen atom, an alkyl group, an aryl group, or an aralkyl groupincludes the member alkyl individually; the subgroup alkyl and aryl; andany other individual member and subgroup subsumed therein.

“Alkyl” means an acyclic, branched or unbranched, saturated monovalenthydrocarbon group. Alkyl is exemplified by, but not limited to, methyl,ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl,1,1-dimethylethyl, pentyl, 1-methylbutyl, 1-ethylpropyl, 2-methylbutyl,3-methylbutyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, hexyl, heptyl,octyl, nonyl, and decyl, as well as branched saturated monovalenthydrocarbon groups of 6 or more carbon atoms.

“Aralkyl” means an alkyl group having a pendant and/or terminal arylgroup or an aryl group having a pendant an alkyl group. Exemplaryaralkyl groups include benzyl, phenylethyl, phenyl propyl, and phenylbutyl.

“Carbocycle” and “carbocyclic” each means a hydrocarbon ring.Carbocycles may be monocyclic or alternatively may be fused, bridged, orspiro polycyclic rings. Monocyclic carbocycles may have 3 to 9 carbonatoms, alternatively 4 to 7 carbon atoms, and alternatively 5 to 6carbon atoms. Polycyclic carbocycles may have 7 to 17 carbon atoms,alternatively 7 to 14 carbon atoms, and alternatively 9 to 10 carbonatoms. Carbocycles may be saturated or partially unsaturated.

“Cycloalkyl” means a saturated carbocycle. Monocyclic cycloalkyl groupsare exemplified by cyclobutyl, cyclopentyl, and cyclohexyl.

“Heterocycle” and “heterocyclic” each mean a ring group comprised ofcarbon atoms and one or more heteroatoms in the ring. The heteroatom maybe N, 0, P, S, or a combination thereof. Heterocycles may be monocyclicor alternatively may be fused, bridged, or spiro polycyclic rings.Monocyclic heterocycles may have 3 to 9 member atoms in the ring,alternatively 4 to 7 member atoms, and alternatively 5 to 6 memberatoms. Polycyclic heterocycles may have 7 to 17 member atoms,alternatively 7 to 14 member atoms, and alternatively 9 to 10 memberatoms. Heterocycles may be saturated or partially unsaturated.

“Halogenated hydrocarbon” means a hydrocarbon where one or more hydrogenatoms bonded to a carbon atom have been formally replaced with a halogenatom. Halogenated hydrocarbon groups include haloalkyl groups,halogenated carbocyclic groups, and haloalkenyl groups. Haloalkyl groupsinclude fluorinated alkyl groups such as trifluoromethyl, fluoromethyl,trifluoroethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl,4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and8,8,8,7,7-pentafluorooctyl; and chlorinated alkyl groups such aschloromethyl and 3-chloropropyl. Halogenated carbocyclic groups includefluorinated cycloalkyl groups such as 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl; and chlorinated cycloalkyl groups suchas 2,2-dichlorocyclopropyl, 2,3-dichlorocyclopentyl. Haloalkenyl groupsinclude allyl chloride.

“Heteroatom” means any of the Group 13-17 elements of the IUPAC PeriodicTable of the Elements athttp://www.iupac.org/fileadmin/user_upload/news/IUPAC_Periodic_Table-1Jun12.pdf,except carbon. “Heteroatom” include, for example, N, 0, P, S, Br, Cl, F,and I.

“Heteroatom containing group” means an organic group comprised ofhydrogen atoms and carbon atoms and that also includes at least oneheteroatom. Heteratom containing groups may include, for example, one ormore of acyl, amide, amine, carboxyl, cyano, epoxy, halogen,hydrocarbonoxy, imino, ketoxime, mercapto, oxo, oxygen, oxime, and/orthiol. For example, when the heteroatom containing group contains one ormore halogen atoms, then the heteroatom containing group may be ahalogenated hydrocarbon group as defined above. Alternatively, when theheteroatom is oxygen, then the heteroatom containing group may be ahydrocarbonoxy group such as an alkoxy group or an alkylalkoxy group.

“Heteroalkyl” group means an acyclic, branched or unbranched, saturatedmonovalent hydrocarbon group that also includes at least one heteroatom.“Heteroalkyl” includes haloalkyl groups and alkyl groups in which atleast one carbon atom has been replaced with a heteroatom such as N, O,P, or S, e.g., when the heteroatom is O, the heteroalkyl group may be analkoxy group.

“Free of” means that the composition contains a non-detectable amount ofthe ingredient, or the composition contains an amount of the ingredientinsufficient to change the visual viscosity measured as described in theExamples section, as compared to the same composition with theingredient omitted. For example, the composition described herein may befree of tin catalysts. “Free of tin catalysts” means that thecomposition contains a non-detectable amount of a tin catalyst capableof catalyzing a condensation reaction with the hydrolyzable groups onother ingredients in the composition, or the composition contains anamount of a tin catalyst insufficient to change the visual viscositymeasured as described in the Examples section, as compared to the samecomposition with the tin catalyst omitted. The composition may be freeof titanium catalysts. “Free of titanium catalysts” means that thecomposition contains a non-detectable amount of a titanium catalystcapable of catalyzing a condensation reaction with the hydrolyzablegroups on other ingredients in the composition, or the compositioncontains an amount of a titanium catalyst insufficient to change thevisual viscosity measured as described in the Examples section, ascompared to the same composition with the titanium catalyst omitted.Alternatively, the composition described herein may be free of metalcondensation reaction catalysts (i.e., other than ingredient (A)described herein). “Free of metal condensation reaction catalysts” meansthat the composition contains a non-detectable amount of a compound of aGroup 3a, 4a, 5a, or 4b metal of the periodic table (as shown inside thefront cover of the CRC Handbook of Chemistry and Physics, 65th ed., CRCPress, Inc., Boca Raton, Fla., 1984), which is capable of catalyzing acondensation reaction, such as compounds of Al, Bi, Sn, Ti, and/or Zr;or an amount of such a metal condensation reaction catalyst insufficientto change the visual viscosity measured as described in the Examplessection as compared to the same composition with the metal condensationreaction catalyst omitted. For purposes of this definition‘non-detectable amount’ may be measured, for example, according to themethod of ASTM D7151-05 Standard Test Method for Determination ofElements in Insulating Oils by Inductively Coupled Plasma AtomicEmission Spectrometry (ICP-AES).

“Non-functional” means that the ingredient, e.g., a polyorganosiloxane,does not have hydrolyzable groups that participate in a condensationreaction.

Abbreviations used herein are defined as follows. The abbreviation “cP”means centiPoise. “DP” means the degree of polymerization of a polymer.“FTIR” means Fourier transform infrared spectroscopy. “GPC” means gelpermeation chromatography. “Mn” means number average molecular weight.Mn may be measured using GPC. “Mw” means weight average molecularweight. “NMR” means nuclear magnetic resonance. “Me” means methyl. “Et”means ethyl. “Ph” means phenyl. “Pr” means propyl and includes variousstructures such as iPr and nPr. “iPr” means isopropyl. “nPr” meansnormal propyl. “Bu” means butyl and includes various structuresincluding nBu, sec-butyl, tBu, and iBu. “iBu” means isobutyl. “nBu”means normal butyl. “tBu” means tert-butyl.

A composition, which has at least one ingredient capable of reacting bycondensation reaction (composition), comprises:

(A) a Zn containing condensation reaction catalyst, and(B) a silicon containing base polymer (base polymer) having an average,per molecule, of one or more hydrolyzable substituents. Without wishingto be bound by theory, it is thought that the Zn containing condensationreaction catalyst is characterizable as being effective for catalyzingthe condensation reaction of the base polymer. The base polymer hashydrolyzable substituents capable of reacting by condensation reaction.The condensation reaction of the base polymer prepares a reactionproduct. The composition may optionally further comprise one or moreadditional ingredients. The one or more additional ingredients aredistinct from ingredients (A) and (B). Suitable additional ingredientsare exemplified by (C) a crosslinker; (D) a drying agent; (E) anextender, a plasticizer, or a combination thereof; (F) a filler; (G) afiller treating agent; (H) a biocide; (J) a flame retardant; (K) asurface modifier; (L) a chain lengthener; (M) an endblocker; (N) anonreactive binder; (O) an anti-aging additive; (P) a water releaseagent; (Q) a pigment; (R) a rheological additive; (S) a vehicle (such asa solvent and/or a diluent); (T) a tackifying agent; (U) a corrosioninhibitor; and a combination thereof.

Ingredient (A) comprises a catalytically effective amount of the Zncontaining condensation reaction catalyst. The Zn containingcondensation reaction catalyst comprises a reaction product of a Znprecursor and a ligand. Without wishing to be bound by theory, it isthought that this reaction product comprises a Zn-ligand complex. The Znprecursor is distinct from a reaction product of the Zn precursor andthe ligand. The Zn precursor is an organic compound of Zn having generalformula (i): Zn-A₂, where each Zn is a Zinc atom, each A isindependently a displaceable substituent. Each A may be a monovalentorganic group. Examples of monovalent organic groups for A includemonovalent hydrocarbon groups, amino groups, silazane groups, carboxylicester groups, and hydrocarbonoxy groups.

Examples of monovalent hydrocarbon groups for A include, but are notlimited to, alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl,heptyl, ethylhexyl, octyl, decyl, dodecyl, undecyl, and octadecyl;alkenyl such as vinyl, allyl, propenyl, and hexenyl; carbocyclic groupsexemplified by saturated carbocyclic groups, e.g., cycloalkyl such ascyclopentyl and cyclohexyl, or unsaturated carbocyclic groups such ascyclopentadienyl or cyclooctadienyl; aryl such as phenyl, tolyl, xylyl,mesityl, and naphthyl; and aralkyl such as benzyl or 2-phenylethyl.Alternatively, each A may be an alkyl group, such as linear and branchedalkyl groups such as methyl, ethyl, iPr, and nBu; and cycloalkyl such ascyclopentyl. Alternatively, each A may be an ethyl group.

Examples of amino groups for A have formula —NA′₂, where each A′ isindependently a hydrogen atom or a monovalent hydrocarbon group.Exemplary monovalent hydrocarbon groups for A′ include, but are notlimited to, alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl,heptyl, ethylhexyl, octyl, decyl, dodecyl, undecyl, and octadecyl;alkenyl such as vinyl, allyl, propenyl, and hexenyl; carbocyclic groupsexemplified by saturated carbocyclic groups, e.g., cycloalkyl such ascyclopentyl and cyclohexyl, or unsaturated carbocyclic groups such ascyclopentadienyl or cyclooctadienyl; aryl such as phenyl, tolyl, xylyl,mesityl, and naphthyl; and aralkyl such as benzyl or 2-phenylethyl.Alternatively, each A′ may be a hydrogen atom or an alkyl group of 1 to4 carbon atoms, such as methyl or ethyl.

Alternatively, each A in general formula (i) may be a silazane group.

Alternatively, each A in general formula (i) may be a carboxylic estergroup. Examples of suitable carboxylic ester groups for A include, butare not limited to ethylhexanoate (such as 2-ethylhexanoate),neodecanoate, octanoate, and stearate. Alternatively, A may be selectedfrom ethylhexanoate and octanoate. Alternatively, each A may be anoctanoate group.

Examples of monovalent hydrocarbonoxy groups for A may have formula—O-A″, where A″ is a monovalent hydrocarbon group. Examples ofmonovalent hydrocarbon groups for A″ include, but are not limited to,alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,ethylhexyl, octyl, decyl, dodecyl, undecyl, and octadecyl; alkenyl suchas vinyl, allyl, propenyl, and hexenyl; cycloalkyl such as cyclopentyland cyclohexyl; aryl such as phenyl, tolyl, xylyl, and naphthyl; aralkylsuch as benzyl or 2-phenylethyl. Alternatively, each A″ may be an alkylgroup, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl,or t-butyl. Alternatively, each A″ may be an alkyl group, andalternatively each A″ may be ethyl, propyl such as iso-propyl orn-propyl, or butyl.

Alternatively, each A may be an alkyl group, such as methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl, or t-butyl. Alternatively,each A may be selected from the group consisting of ethyl, benzyl,mesityl, phenyl,-NEt₂, cyclooctadiene, ethoxide, iso-propoxide,butoxide, 2-ethylhexanoate, neodecanoate, octanoate, and stearate.

Organic compounds of Zn suitable for use as precursors are commerciallyavailable. For example, dialkyl zinc compounds such as Zn-Et₂ and diarylzinc compounds such as compounds of zinc such as Zn-Ph₂ are commerciallyavailable from Sigma-Aldrich of St. Louis, Mo., U.S.A. Diesters of zinc,such as Zn(octanoate)₂, are commercially available from City ChemicalsLLC of West Haven, Conn., U.S.A.

The ligand is an organic compound that coordinates with Zn. The organiccompound includes neutral and conjugate base forms. Without wishing tobe bound by theory, it is thought that the ligand displaces one or moreinstances of displaceable substituent A in the Zn precursor. The ligandmay have general formula (ii):

In general formula (ii), a bond with ‘Rn’ in the formula represents acovalent single bond or an aromatic bond forming part of a ringstructure. Q¹ is a heteroatom, which may be selected from O and S.

In general formula (ii), each A² and each A³ is independently selectedfrom a hydrogen atom and a monovalent hydrocarbon group. Suitablemonovalent hydrocarbon groups include alkyl groups of 1 to 8 carbonatoms, carbocyclic groups of 5 or 6 carbon atoms, aryl groups of 6 to 9carbon atoms, and aralkyl groups of 6 to 11 carbon atoms. Alternatively,each A² and each A³ is an aryl group.

In general formula (ii), each of A⁴, A⁵, A⁶, and A⁷ is independentlyselected from a hydrogen atom and a monovalent organic group. Themonovalent organic group may be a monovalent hydrocarbon group or amonovalent heteroatom containing group such as a monovalent halogenatedhydrocarbon group. Suitable monovalent hydrocarbon groups include alkylgroups of 1 to 8 carbon atoms, carbocyclic groups of 5 or 6 carbonatoms, aryl groups of 6 to 9 carbon atoms, and aralkyl groups of 6 to 11carbon atoms. Alternatively, A⁵ and A⁶ may be bonded together to form aring structure such as a carbocycle, an aryl group, an aralkyl group ora heterocyclic group. When A⁵ and A⁶ are bonded together to form a ring,then A⁴ and A⁷ may be H.

In general formula (v), A¹ is either a monovalent hydrocarbon group or adivalent linking group. Suitable monovalent hydrocarbon groups for A¹include alkyl, aryl, and aralkyl. Examples of divalent linking groupsfor A¹ include alkylene such as ethylene, propylene, or hexylene;arylene such as phenylene, or alkylarylene such as:

When A¹ is a divalent linking group, then A¹ may link the structure ofgeneral formula (ii) with a structure of general formula (iii):

where A², A³, A⁴, A⁵, A⁶, and A⁷ are as defined above. Examples ofligands of general formula (ii) include Ligand 1 and Ligand 2 shown inTable 1.

The neutral forms of suitable ligands of general formula (ii) are shownbelow in Table 1.

TABLE 1 Ligands Ligand Structure 1

2

3

Certain ligands in Table 1 are commercially available. For example,ligand 1 is 2-(2-METHOXYPHENYL)-4,5-DIPHENYL-1H-IMIDAZOLE fromSigma-Aldrich of St. Louis, Mo., U.S.A. Ligand 3 is commerciallyavailable from Strem Chemicals, Inc. of Newburyport, Mass., U.S.A.

The ligand used to prepare ingredient (A) may be a ligand shown inTable 1. Alternatively, the ligand may be selected depending on variousfactors including the selection of precursor. For example, when theprecursor is a dialkyl zinc compound, such as diethyl zinc, then theligand may be ligand 2 from Table 1. Alternatively, when the precursoris a diester zinc compound, such as zinc dioctanoate, then the ligandmay be ligand 1 from Table 1.

Ingredient (A) may be prepared by a method comprising reacting theligand and the Zn precursor, described above, thereby forming acatalytically active reaction product comprising the Zn-ligand complex.The method may optionally further comprise a step of dissolving eitherthe Zn precursor, or the ligand, or both, in a solvent before combiningthe Zn precursor and the ligand. Suitable solvents are exemplified bythose described below for ingredient (S). Alternatively, the ligand maybe dissolved in a solvent in a container, and the solvent may thereafterbe removed before adding the Zn precursor to the container with theligand. The amounts of ligand and Zn precursor are selected such thatthe mole ratio of ligand to Zn precursor (Ligand:Metal Ratio) may rangefrom 1:1 to 10:1, alternatively 1:1 to 3:1, and alternatively 1:1 to2:1. Combining the Zn precursor and the ligand may be performed by anyconvenient means, such as mixing them together in or shaking thecontainer.

Reacting the Zn precursor and ligand may be performed by any convenientmeans such as allowing the Zn precursor and ligand prepared as describedabove to react at room temperature (RT) of 25° C. for a period of time,or by heating. Heating may be performed by any convenient means, such asvia a heating mantle, heating coil, or placing the container in an oven.The reaction temperature depends on various factors including thereactivities of the specific Zn precursor and ligand selected and theLigand:Metal Ratio, however, temperature may range from 25° C. to 200°C., alternatively 25° C. to 75° C. Reaction time depends on variousfactors including the reaction temperature selected, however, reactiontime may range from 1 minute to 48 hours, alternatively 45 minutes (min)to 60 min. The ligand and Zn precursor may be combined and heatedsequentially. Alternatively, the ligand and Zn precursor may be combinedand heated concurrently.

The method of preparing the catalytically active reaction product ofingredient (A) may optionally further comprise adding a solvent afterthe reaction. Suitable solvents are exemplified by those described belowfor ingredient (S). Alternatively, the method may optionally furthercomprise removing a reaction by-product and/or the solvent, if thesolvent is present (e.g., used to facilitate combination of the Znprecursor and the ligand before or during heating). By-products include,for example, H-A (where A is as defined above in general formula (i)) orany species resulting from reacting an organic group off the Znprecursor when the ligand reacts with the Zn precursor. By-products maybe removed by any convenient means, such as stripping or distillation,with heating or under vacuum, or a combination thereof. The resultingisolated Zn-ligand complex may be used as the catalytically activereaction product of ingredient (A).

Alternatively, the reaction by-products are not removed before using thecatalytically active reaction product as ingredient (A). For example,the ligand and Zn precursor may be reacted as described above, with orwithout solvent removal, and the resulting catalytically active reactionproduct (comprising the Zn-ligand complex and the reaction by-productand optionally a solvent or diluent) may be used as ingredient (A).Without wishing to be bound by theory, it is thought that a by-productmay act as a condensation reaction catalyst in addition to the Zn-ligandcomplex, or as a co-catalyst or an activator for the Zn-ligand complex.Therefore, the reaction product may catalyze a condensation reaction.

The composition may contain one single catalyst. Alternatively, thecomposition may comprise two or more catalysts described above asingredient (A), where the two or more catalysts differ in at least oneproperty such as selection of ligand, selection of precursor,Ligand:Metal Ratio, and definitions for group A in general formula (i).The composition may be free of tin catalysts, alternatively thecomposition may be free of titanium catalysts, and alternatively thecomposition may be both free of tin catalysts and free of titaniumcatalysts. Alternatively, the composition may be free of any Zn compoundthat would catalyze the condensation reaction of the hydrolyzable groupson ingredient (B) other than ingredient (A). Alternatively, thecomposition may be free of metal condensation reaction catalysts otherthan ingredient (A). Alternatively, the composition may be free of anyingredient that would catalyze the condensation reaction of thehydrolyzable groups on ingredient (B) other than ingredient (A).

Ingredient (A) is present in the composition in a catalyticallyeffective amount. The exact amount depends on various factors includingreactivity of ingredient (A), the type and amount of ingredient (B), andthe type and amount of any additional ingredient, if present. However,the amount of ingredient (A) in the composition may range from 1 partper million (ppm) to 5%, alternatively 0.1% to 2%, and alternatively 1ppm to 1%, based on total weight of all ingredients in the composition.

Ingredient (B) is a silicon containing base polymer (base polymer).Ingredient (B) comprises a polymer backbone having an average, permolecule, of one or more hydrolyzable substituents covalently bondedthereto. Alternatively, the one or more hydrolyzable substituents arehydrolyzable silyl substituents. The polymer backbone may be selectedfrom a polyorganosiloxane such as a polydiorganosiloxane, an organicpolymer backbone, or a silicone-organic copolymer backbone (having theone or more hydrolyzable silyl substituents covalently bonded to an atomin the polymer backbone). Alternatively, the polymer backbone ofingredient (B) may be a polyorganosiloxane backbone, or an organicbackbone. Alternatively, the polymer backbone of ingredient (B) may be apolyorganosiloxane backbone. The hydrolyzable substituents areexemplified by hydrogen atoms; halogen atoms; amido groups such asacetamido groups, benzamido groups, or methylacetamido groups; acyloxygroups such as acetoxy groups; hydrocarbonoxy groups such as alkoxygroups or alkenyloxy groups; amino groups; aminoxy groups; hydroxylgroups; mercapto groups; oximo groups; ketoximo groups;alkoxysilylhydrocarbylene groups; or a combination thereof.Alternatively, ingredient (B) may have an average of two or morehydrolyzable substituents per molecule. The hydrolyzable substituent iningredient (B) may be located at terminal, pendant, or both terminal andpendant positions on the polymer backbone. Alternatively, thehydrolyzable substituent in ingredient (B) may be located at one or moreterminal positions on the polymer backbone. Ingredient (B) may comprisea linear, branched, cyclic, or resinous structure. Alternatively,ingredient (B) may comprise a linear, branched or cyclic structure.Alternatively, ingredient (B) may comprise a linear or branchedstructure. Alternatively, ingredient (B) may comprise a linearstructure. Alternatively, ingredient (B) may comprise a linear structureand a resinous structure. Ingredient (B) may comprise a homopolymer or acopolymer or a combination thereof.

Ingredient (B) may have the hydrolyzable substituents contained ingroups of the formula (ii):

where each D independently represents an oxygen atom, a divalent organicgroup, a divalent silicone organic group, or a combination of a divalenthydrocarbon group and a divalent siloxane group; each X independentlyrepresents a hydrolyzable substituent; each R independently represents amonovalent hydrocarbon group; subscript c represents 0, 1, 2, or 3;subscript a represents 0, 1, or 2; and subscript b has a value of 0 orgreater, with the proviso that the sum of (a+c) is at least 1, suchthat, on average, at least one X is present in the formula.Alternatively, subscript b may have a value ranging from 0 to 18.

Alternatively, each D may be independently selected from an oxygen atomand a divalent hydrocarbon group. Alternatively, each D may be an oxygenatom. Alternatively, each D may be a divalent hydrocarbon groupexemplified by an alkylene group such as ethylene, propylene, butylene,or hexylene; an arylene group such as phenylene, or an alkylarylenegroup such as:

Alternatively, an instance of D may be an oxygen atom while a differentinstance of D is a divalent hydrocarbon group.

Alternatively, each X may be a hydrolyzable substituent independentlyselected from the group consisting of an alkoxy group; an alkenyloxygroup; an amido group, such as an acetamido, a methylacetamido group, orbenzamido group; an acyloxy group such as acetoxy; an amino group; anaminoxy group; a hydroxyl group; a mercapto group; an oximo group; aketoximo group; and a halogen atom. Alternatively, each X may beindependently selected from the group consisting of an alkoxy group, anamido group, an acyloxy group, an amino group, a hydroxyl group, and anoximo group.

Alternatively, each R in the formula above may be independently selectedfrom alkyl groups of 1 to 20 carbon atoms, aryl groups of 6 to 20 carbonatoms, and aralkyl groups of 7 to 20 carbon atoms.

Alternatively, subscript b may be 0.

Ingredient (B) may comprise the groups described by formula (ii) abovein an amount of the base polymer ranging from 0.2 mol % to 10 mol %,alternatively 0.5 mol % to 5 mol %, alternatively 0.5 mol % to 2.0 mol%, alternatively 0.5 mol % to 1.5 mol %, and alternatively 0.6 mol % to1.2 mol %.

Ingredient (B) may have a polyorganosiloxane backbone with a linearstructure, i.e., a polydiorganosiloxane backbone. When ingredient (B)has a polydiorganosiloxane backbone, ingredient (B) may comprise analkoxy-endblocked polydiorganosiloxane, analkoxysilylhydrocarbylene-endblocked polydiorganosiloxane, ahydroxyl-endblocked polydiorganosiloxane, or a combination thereof.

Ingredient (B) may comprise a polydiorganosiloxane of formula (I):

where each R¹ is independently a hydrolyzable substituent, each R² isindependently a monovalent organic group, each R³ is independently anoxygen atom or a divalent hydrocarbon group, each subscript d isindependently 1, 2, or 3, and subscript e is an integer having a valuesufficient to provide the polydiorganosiloxane with a viscosity of atleast 100 mPa·s at 25° C. and/or a DP of at least 87. DP may be measuredby GPC using polystyrene standards calibration. Alternatively, subscripte may have a value ranging from 1 to 200,000.

Suitable hydrolyzable substituents for R¹ include, but are not limitedto, the hydrolyzable substituents described above for group X.Alternatively, the hydrolyzable substituents for R¹ may be selected froma halogen atom, an acetamido group, an acyloxy group such as acetoxy, analkoxy group, an amido group, an amino group, an aminoxy group, ahydroxyl group, an oximo group, a ketoximo group, and a methylacetamidogroup.

Suitable organic groups for R² include, but are not limited to,monovalent organic groups such as hydrocarbon groups and halogenatedhydrocarbon groups. Examples of monovalent hydrocarbon groups for R²include, but are not limited to, alkyl such as methyl, ethyl, propyl,pentyl, octyl, decyl, dodecyl, undecyl, and octadecyl; cycloalkyl suchas cyclopentyl and cyclohexyl; aryl such as phenyl, tolyl, xylyl, andbenzyl; and aralkyl such as 2-phenylethyl. Examples of monovalenthalogenated hydrocarbon groups for R² include, but are not limited to,chlorinated alkyl groups such as chloromethyl and chloropropyl groups;fluorinated alkyl groups such as fluoromethyl, 2-fluoropropyl,3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and8,8,8,7,7-pentafluorooctyl; chlorinated cycloalkyl groups such as2,2-dichlorocyclopropyl, 2,3-dichlorocyclopentyl; and fluorinatedcycloalkyl groups such as 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl. Examples of other monovalent organicgroups for R² include, but are not limited to, hydrocarbon groupssubstituted with oxygen atoms such as glycidoxyalkyl, and hydrocarbongroups substituted with nitrogen atoms such as aminoalkyl andcyano-functional groups such as cyanoethyl and cyanopropyl.Alternatively, each R² may be an alkyl group such as methyl.

Ingredient (B) may comprise an α,ω-difunctional-polydiorganosiloxanewhen, in formula (I) above, each subscript d is 1 and each R³ is anoxygen atom. For example, ingredient (B) may have formula (II): R¹R²₂SiO-(R² ₂SiO)_(e)—SiR² ₂R¹, where R¹ and R² are as described above andsubscript e′ is an integer having a value sufficient to give thepolydiorganosiloxane of formula (II) the viscosity described above.Alternatively, subscript e′ may have a value ranging from 1 to 200,000,alternatively 50 to 1,000, and alternatively 200 to 700.

Alternatively, ingredient (B) may comprise a hydroxyl-functionalpolydiorganosiloxane of formula (II) described above, in which each R¹may be a hydroxyl group, each R² may be an alkyl group such as methyl,and subscript e′ may have a value such that the hydroxyl functionalpolydiorganosiloxane has a viscosity of at least 100 mPa·s at 25° C.Alternatively, subscript e′ may have a value ranging from 50 to 700.Exemplary hydroxyl-endblocked polydiorganosiloxanes arehydroxyl-endblocked polydimethylsiloxanes. Hydroxyl-endblockedpolydiorganosiloxanes suitable for use as ingredient (B) may be preparedby methods known in the art, such as hydrolysis and condensation of thecorresponding organohalosilanes or equilibration of cyclicpolydiorganosiloxanes.

Alternatively, ingredient (B) may comprise analkoxysilylhydrocarbylene-endblocked polydiorganosiloxane, for example,when in formula (I) above each R³ is divalent hydrocarbon group or acombination of a divalent hydrocarbon group and a divalent siloxanegroup. Each R³ may be an alkylene group such as ethylene, propylene, orhexylene; an arylene group such as phenylene, or an alkylarylene groupsuch as:

Alternatively, each R¹ and each R² may be alkyl, each R³ may be alkylenesuch as ethylene, and each subscript d may be 3.

Alkoxysilylhydrocarbylene-endblocked polydiorganosiloxanes may beprepared by reacting a vinyl-terminated, polydimethylsiloxane with(alkoxysilylhydrocarbyl)tetramethyldisiloxane.

Alternatively, ingredient (B) may comprise a moisture-curable,silane-functional, organic polymer. Alternatively, the organic polymermay be a polymer in which at least half the atoms in the polymerbackbone are carbon atoms with terminal moisture curable silyl groupscontaining hydrolyzable substituents bonded to silicon atoms. Theorganic polymer can, for example, be selected from hydrocarbon polymers,polyethers, acrylate polymers, polyurethanes and polyureas.

Ingredient (B) may be elastomeric, i.e., have a glass transitiontemperature (Tg) less than 0° C. When ingredient (B) is elastomeric,ingredient (B) may be distinguished, based on the Tg, fromsemi-crystalline and amorphous polyolefins (e.g., alpha-olefins),commonly referred to as thermoplastic polymers.

Ingredient (B) may comprise a silylated poly(alpha-olefin), a silylatedcopolymer of an iso-mono-olefin and a vinyl aromatic monomer, asilylated copolymer of a diene and a vinyl aromatic monomer, a silylatedcopolymer of an olefin and a diene (e.g., a silylated butyl rubberprepared from polyisobutylene and isoprene, which may optionally behalogenated), or a combination thereof (silylated copolymers), asilylated homopolymer of the iso-mono-olefin, a silylated homopolymer ofthe vinyl aromatic monomer, a silylated homopolymer of the diene (e.g.,silylated polybutadiene or silylated hydrogenated polybutadiene), or acombination thereof (silylated homopolymers) or a combination silylatedcopolymers and silylated homopolymers. For purposes of this application,silylated copolymers and silylated homopolymers are referred tocollectively as ‘silylated polymers’. The silylated polymer mayoptionally contain one or more halogen groups, particularly brominegroups, covalently bonded to an atom of the silylated polymer.

Examples of suitable mono-iso-olefins include, but are not limited to,isoalkylenes such as isobutylene, isopentylene, isohexylene, andisoheptylene; alternatively isobutylene. Examples of suitable vinylaromatic monomers include but are not limited to alkylstyrenes such asalpha-methylstyrene, t-butylstyrene, and para-methylstyrene;alternatively para-methylstyrene. Examples of suitable alkyl groupsinclude methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, andt-butyl; alternatively methyl. Examples of suitable alkenyl groupsinclude, vinyl, allyl, propenyl, butenyl, and hexenyl; alternativelyvinyl. The silylated organic polymer may have Mn ranging from 20,000 to500,000, alternatively 50,000-200,000, alternatively 20,000 to 100,000,alternatively 25,000 to 50,000, and alternatively 28,000 to 35,000;where values of Mn are expressed in grams per mole (g/mol) and weremeasured by Triple Detection Size Exclusion Chromatography andcalculated on the basis of polystyrene molecular weight standards.

Examples of suitable silylated poly(alpha-olefins) are known in the artand are commercially available. Examples include the condensationreaction curable silylated polymers marketed as VESTOPLAST®, which arecommercially available from Degussa AG Coatings & Colorants of Marl,Germany, Europe.

Briefly stated, a method for preparing the silylated copolymers involvescontacting i) an olefin copolymer having at least 50 mole % of repeatunits comprising residuals of an iso-mono-olefin having 4 to 7 carbonatoms and at most 50 mole % of repeat units comprising residuals of avinyl aromatic monomer; ii) a silane having at least two hydrolyzablegroups and at least one olefinically unsaturated hydrocarbon orhydrocarbonoxy group; and iii) a free radical generating agent.

Alternatively, silylated copolymers may be prepared by a methodcomprising conversion of commercially available hydroxylatedpolybutadienes (such as those commercially available from Cray Valley SAof Paris, France, under trade names Poly BD and Krasol) by known methods(e.g., reaction with isocyanate functional alkoxysilane, reaction withallylchloride in presence of Na followed by hydrosilylation).

Alternatively, examples of suitable silyl modified hydrocarbon polymersinclude silyl modified polyisobutylene, which is available commerciallyin the form of telechelic polymers. Silyl modified polyisobutylene can,for example, contain curable silyl groups derived from asilyl-substituted alkyl acrylate or methacrylate monomer such as adialkoxyalkylsilylpropyl methacrylate or trialkoxysilylpropylmethacrylate, which can be reacted with a polyisobutylene prepared byliving anionic polymerisation, atom transfer radical polymerization orchain transfer polymerization.

Alternatively, ingredient (B) may comprise a polyether. One type ofpolyether is a polyoxyalkylene polymer comprising recurring oxyalkyleneunits of the formula (—C_(t)H_(2t)—O—) where subscript t is an integerwith a value ranging from 2 to 4. Polyoxyalkylene polymers typicallyhave terminal hydroxyl groups, and can readily be terminated with silylgroups having hydrolyzable substituents bonded to silicon atoms, forexample by reaction of the terminal hydroxyl groups with an excess of analkyltrialkoxysilane to introduce terminal alkyldialkoxysilyl groups.Alternatively, polymerization may occur via a hydrosilylation typeprocess. Polyoxyalkylenes comprising mostly oxypropylene units may haveproperties suitable for many sealant uses. Polyoxyalkylene polymers,particularly polyoxypropylenes, having terminal alkyldialkoxysilyl ortrialkoxysilyl groups may react with each other in the presence ofingredient (A) and moisture. The composition containing these basepolymers may optionally further comprise a crosslinker.

The organic polymer having hydrolysable silyl groups can alternativelybe an acrylate polymer, that is an addition polymer of acrylate and/ormethacrylate ester monomers, which may comprise at least 50 mole % ofthe monomer repeat units in the acrylate polymer. Examples of suitableacrylate ester monomers are n-butyl, isobutyl, n-propyl, ethyl, methyl,n-hexyl, n-octyl and 2-ethylhexyl acrylates. Examples of suitablemethacrylate ester monomers are n-butyl, isobutyl, methyl, n-hexyl,n-octyl, 2-ethylhexyl and lauryl methacrylates. For some applications,the acrylate polymer may have a Tg below ambient temperature; andacrylate polymers may form lower Tg polymers than methacrylate polymers.An exemplary acrylate polymer is polybutyl acrylate. The acrylatepolymer may contain lesser amounts of other monomers such as styrene,acrylonitrile or acrylamide. The acrylate polymer can be prepared byvarious methods such as conventional radical polymerization, or livingradical polymerization such as atom transfer radical polymerization,reversible addition-fragmentation chain transfer polymerization, oranionic polymerization including living anionic polymerization. Thecurable silyl groups can, for example, be derived from asilyl-substituted alkyl acrylate or methacrylate monomer. Hydrolysablesilyl groups such as dialkoxyalkylsilyl or trialkoxysilyl groups can,for example, be derived from a dialkoxyalkylsilylpropyl methacrylate ortrialkoxysilylpropyl methacrylate. When the acrylate polymer has beenprepared by a polymerization process which forms reactive terminalgroups, such as atom transfer radical polymerization, chain transferpolymerization, or living anionic polymerization, it can readily bereacted with the silyl-substituted alkyl acrylate or methacrylatemonomer to form terminal hydrolyzable silyl groups.

Silyl modified polyurethanes or polyureas can, for example, be preparedby the reaction of polyurethanes or polyureas having terminalethylenically unsaturated groups with a silyl monomer containinghydrolyzable groups and a Si—H group, for example a dialkoxyalkylsiliconhydride or trialkoxysilicon hydride.

Alternatively, the base polymer may have a silicone-organic blockcopolymer backbone, which comprises at least one block ofpolyorganosiloxane groups and at least one block of an organic polymerchain. The polyorganosiloxane groups may comprise groups of formula —(R⁴_(f)SiO_((4-f)/2))—, in which each R⁴ is independently an organic groupsuch as a hydrocarbon group having from 1 to 18 carbon atoms, ahalogenated hydrocarbon group having from 1 to 18 carbon atoms such aschloromethyl, perfluorobutyl, trifluoroethyl, and nonafluorohexyl, ahydrocarbonoxy group having up to 18 carbon atoms, or another organicgroup exemplified by an oxygen atom containing group such as(meth)acrylic or carboxyl; a nitrogen atom containing group such asamino-functional groups, amido-functional groups, and cyano-functionalgroups; a sulfur atom containing group such as mercapto groups; andsubscript f has, on average, a value ranging from 1 to 3, alternatively1.8 to 2.2.

Alternatively, each R⁴ may be a hydrocarbon group having 1 to 10 carbonatoms or a halogenated hydrocarbon group; and subscript f may be 0, 1 or2. Examples of groups suitable for R⁴ include methyl, ethyl, propyl,butyl, vinyl, cyclohexyl, phenyl, tolyl group, a propyl groupsubstituted with chlorine or fluorine such as 3,3,3-trifluoropropyl,chlorophenyl, beta-(perfluorobutyl)ethyl or chlorocyclohexyl group.

The organic blocks in the polymer backbone may comprise, for example,polystyrene and/or substituted polystyrenes such aspoly(α-methylstyrene), poly(vinylmethylstyrene), dienes,poly(p-trimethylsilylstyrene) andpoly(p-trimethylsilyl-α-methylstyrene). Other organic groups, which maybe incorporated in the polymer backbone, may include acetyleneterminated oligophenylenes, vinylbenzyl terminated aromaticpolysulphones oligomers, aromatic polyesters, aromatic polyester basedmonomers, polyalkylenes, polyurethanes, aliphatic polyesters, aliphaticpolyamides and aromatic polyamides.

Alternatively, the organic polymer blocks in a siloxane organic blockcopolymer for ingredient (B) may be polyoxyalkylene based blockscomprising recurring oxyalkylene units, illustrated by the averageformula (—C_(g)H_(2g)—O—)_(h) where subscript g is an integer with avalue ranging from 2 to 4 and subscript h is an integer of at leastfour. The number average molecular weight (Mn) of each polyoxyalkylenepolymer block may range from 300 to 10,000. Moreover, the oxyalkyleneunits are not necessarily identical throughout the polyoxyalkyleneblock, but can differ from unit to unit. A polyoxyalkylene block, forexample, can comprise oxyethylene units (—C₂H₄—O—), oxypropylene units(—C₃H₆—O—) or oxybutylene units (—C₄H₈—O—), or combinations thereof.Alternatively, the polyoxyalkylene polymeric backbone may consistessentially of oxyethylene units and/or oxypropylene units. Otherpolyoxyalkylene blocks may include for example, units of the structure:—[—R⁵—O—(—R⁶—O—)_(i)-Pn-CR⁷ ₂-Pn-O—(—R⁶—O—)_(j)—R⁵]—, in which Pn is a1,4-phenylene group, each R⁵ is the same or different and is a divalenthydrocarbon group having 2 to 8 carbon atoms, each R⁶ is the same ordifferent and is an ethylene group or propylene group, each R⁷ is thesame or different and is a hydrogen atom or methyl group and each of thesubscripts i and j each represent a positive integer having a valueranging from 3 to 30.

Alternatively, ingredient (B) may comprise a silicone resin, in additionto, or instead of, one of the polymers described above for ingredient(B). Suitable silicone resins are exemplified by an MQ resin, whichcomprises siloxane units of the formulae: R²⁹ _(w)R³⁰ _((3-w))SiO_(1/2)and SiO_(4/2), where R²⁹ and R³⁰ are monovalent organic groups, such asmonovalent hydrocarbon groups exemplified by alkyl such as methyl,ethyl, propyl, pentyl, octyl, decyl, dodecyl, undecyl, and octadecyl;cycloalkyl such as cyclopentyl and cyclohexyl; aryl such as phenyl,tolyl, xylyl, and benzyl; and aralkyl such as 2-phenylethyl; halogenatedhydrocarbon group exemplified by chlorinated alkyl groups such aschloromethyl and chloropropyl groups; fluorinated alkyl groups such asfluoromethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl,4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and8,8,8,7,7-pentafluorooctyl; chlorinated cycloalkyl groups such as2,2-dichlorocyclopropyl, 2,3-dichlorocyclopentyl; and fluorinatedcycloalkyl groups such as 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl; and other monovalent organic groupssuch as hydrocarbon groups substituted with oxygen atoms such asglycidoxyalkyl, and hydrocarbon groups substituted with nitrogen atomssuch as aminoalkyl and cyano-functional groups such as cyanoethyl andcyanopropyl; and each instance of subscript w is 0, 1, or 2.Alternatively, each R²⁹ and each R³⁰ may be an alkyl group. The MQ resinmay have a molar ratio of M units to Q units (M:Q) ranging from 0.5:1 to1.5:1. These mole ratios are conveniently measured by Si²⁹NMRspectroscopy. This technique is capable of quantitatively determiningthe concentration of R²⁹ ₃SiO_(1/2) (“M”) and SiO_(4/2) (“Q”) unitsderived from the silicone resin and from the neopentamer, Si(OSiMe₃)₄,present in the initial silicone resin, in addition to the total hydroxylcontent of the silicone resin.

The MQ silicone resin is soluble in solvents such as liquid hydrocarbonsexemplified by benzene, toluene, xylene, and heptane, or in liquidorganosilicon compounds such as a low viscosity cyclic and linearpolydiorganosiloxanes.

The MQ silicone resin may contain 2.0% or less, alternatively 0.7% orless, alternatively 0.3% or less, of terminal units represented by theformula X″SiO_(3/2), where X″ represents hydroxyl or a hydrolyzablegroup such as alkoxy such as methoxy and ethoxy; alkenyloxy such asisopropenyloxy; ketoximo such as methyethylketoximo; carboxy such asacetoxy; amidoxy such as acetamidoxy; and aminoxy such asN,N-dimethylaminoxy. The concentration of silanol groups present in thesilicone resin can be determined using FTIR.

The Mn desired to achieve the desired flow characteristics of the MQsilicone resin can depend at least in part on the Mn of the siliconeresin and the type of organic group, represented by R²⁹, that arepresent in this ingredient. The Mn of the MQ silicone resin is typicallygreater than 3,000, more typically from 4500 to 7500.

The MQ silicone resin can be prepared by any suitable method. Siliconeresins of this type have reportedly been prepared by cohydrolysis of thecorresponding silanes or by silica hydrosol capping methods known in theart. Briefly stated, the method involves reacting a silica hydrosolunder acidic conditions with a hydrolyzable triorganosilane such astrimethylchlorosilane, a siloxane such as hexamethyldisiloxane, or acombination thereof, and recovering a product comprising M and Q units(MQ resin). The resulting MQ resins may contain from 2 to 5 percent byweight of silicon-bonded hydroxyl groups.

The intermediates used to prepare the MQ silicone resin may betriorganosilanes of the formula R²⁹ ₃SiX, where X represents ahydrolyzable group, as described above for ingredient (B), and either asilane with four hydrolyzable groups such as halogen, alkoxy orhydroxyl, or an alkali metal silicate such as sodium silicate.

In some compositions, it may be desirable that the amount ofsilicon-bonded hydroxyl groups (i.e., HOR²⁹SiO_(1/2) or HOSiO_(3/2)groups) in the silicone resin be below 0.7% by weight of the totalweight of the silicone resin, alternatively below 0.3%. Silicon-bondedhydroxyl groups formed during preparation of the silicone resin areconverted to trihydrocarbylsiloxy groups or a hydrolyzable group byreacting the silicone resin with a silane, disiloxane or disilazanecontaining the appropriate terminal group. Silanes containinghydrolyzable groups may be added in excess of the stoichiometricquantity of the silicon-bonded hydroxyl groups of the silicone resin.

Various suitable MQ resins are commercially available from sources suchas Dow Corning Corporation of Midland, Mich., U.S.A., MomentivePerformance Materials of Albany, N.Y., U.S.A., and Bluestar SiliconesUSA Corp. of East Brunswick, N.J., U.S.A. For example, DOW CORNING®MQ-1600 Solid Resin, DOW CORNING® MQ-1601 Solid Resin, and DOW CORNING®1250 Surfactant, DOW CORNING® 7466 Resin, and DOW CORNING® 7366 Resin,all of which are commercially available from Dow Corning Corporation,are suitable for use in the methods described herein. Alternatively, aresin containing M, T, and Q units may be used, such as DOW CORNING®MQ-1640 Flake Resin, which is also commercially available from DowCorning Corporation. Such resins may be supplied in organic solvent.

Alternatively, the silicone resin may comprise a silsesquioxane resin,i.e., a resin containing T units of formula (R³¹SiO_(3/2)). Each R³¹ maybe independently selected from a hydrogen atom and a monovalent organicgroup, such as a monovalent hydrocarbon group exemplified by alkyl suchas methyl, ethyl, propyl, pentyl, octyl, decyl, dodecyl, undecyl, andoctadecyl; cycloalkyl such as cyclopentyl and cyclohexyl; aryl such asphenyl, tolyl, xylyl, and benzyl; and aralkyl such as 2-phenylethyl;halogenated hydrocarbon group exemplified by chlorinated alkyl groupssuch as chloromethyl and chloropropyl groups; a fluorinated alkyl groupsuch as fluoromethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl,4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and8,8,8,7,7-pentafluorooctyl; chlorinated cycloalkyl groups such as2,2-dichlorocyclopropyl, 2,3-dichlorocyclopentyl; and fluorinatedcycloalkyl groups such as 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl; and another monovalent organic groupsuch as a hydrocarbon group substituted with oxygen atoms such asglycidoxyalkyl, and a hydrocarbon group substituted with a nitrogen atomsuch as aminoalkyl and cyano-functional groups such as cyanoethyl andcyanopropyl. Silsesquioxane resins suitable for use herein are known inthe art and are commercially available. For example, amethylmethoxysiloxane methylsilsesquioxane resin having a DP of 15 and aweight average molecular weight (Mw) of 1200 g/mol is commerciallyavailable as DOW CORNING® US-CF 2403 Resin from Dow Corning Corporationof Midland, Mich., U.S.A. Alternatively, the silsesquioxane resin mayhave phenylsilsesquioxane units, methylsilsesquioxane units, or acombination thereof. Such resins are known in the art and arecommercially available as DOW CORNING® 200 Flake resins, also availablefrom Dow Corning Corporation. Alternatively, the silicone resin maycomprise D units of formulae (R³¹ ₂SiO_(2/2)) and/or (R³¹R³²SiO_(2/2))and T units of formulae (R³¹SiO_(3/2)) and/or (R³²SiO_(3/2)), i.e., a DTresin, where R³¹ is as described above and R³² is a hydrolyzable groupsuch as group X described above. DT resins are known in the art and arecommercially available, for example, methoxy functional DT resinsinclude DOW CORNING® 3074 and DOW CORNING® 3037 resins; and silanolfunctional resins include DOW CORNING® 800 Series resins, which are alsocommercially available from Dow Corning Corporation. Other suitableresins include DT resins containing methyl and phenyl groups.

The amount of silicone resin added to the composition can vary dependingon the end use of the composition. For example, when the reactionproduct of the composition is a gel, little or no silicone resin may beadded. However, the amount of silicone resin in the composition mayrange from 0% to 90%, alternatively 0.1% to 50%, based on the weight ofall ingredients in the composition.

The amount of ingredient (B) can depend on various factors including theend use of the reaction product of the composition, the type of basepolymer selected for ingredient (B), and the type(s) and amount(s) ofany additional ingredient(s) present, if any. However, the amount ofingredient (B) may range from 0.01% to 99%, alternatively 10% to 95%,alternatively 10% to 65% of the composition.

Ingredient (B) can be one single base polymer or a combinationcomprising two or more base polymers that differ in at least one of thefollowing properties: average molecular weight, hydrolyzablesubstituents, siloxane units, sequence, and viscosity. When one basepolymer for ingredient (B) contains an average of only one to twohydrolyzable substituents per molecule, then the composition further mayfurther comprise an additional base polymer having an average of morethan two hydrolyzable substituents per molecule, or ingredient (C) acrosslinker, or both.

The composition may optionally further comprise one or more additionalingredients, i.e., in addition to ingredients (A) and (B) and distinctfrom ingredients (A) and (B). The additional ingredient, if present, maybe selected based on factors such as the method of use of thecomposition and/or the end use of the cured product of the composition.The additional ingredient may be: (C) a crosslinker; (D) a drying agent;(E) an extender, a plasticizer, or a combination thereof; (F) a fillersuch as (f1) a reinforcing filler, (f2) an extending filler, (f3) aconductive filler (e.g., electrically conductive, thermally conductive,or both); (G) a filler treating agent; (H) a biocide, such as (h1) afungicide, (h2) an herbicide, (h3) a pesticide, or (h4) anantimicrobial; (J) a flame retardant; (K) a surface modifier such as(k1) an adhesion promoter or (k2) a release agent; (L) a chainlengthener; (M) an endblocker; (N) a nonreactive binder; (O) ananti-aging additive; (P) a water release agent; (Q) a pigment; (R) arheological additive; (S) a vehicle; (T) a tackifying agent; (U) acorrosion inhibitor; and a combination thereof. The additionalingredients are distinct from one another. In some embodiments at leastone, alternatively each of additional ingredients (C) to (U), and thecombination thereof, does not completely prevent the condensationreaction of ingredient (B).

Ingredient (C) is a crosslinker that may be added to the composition,for example, when ingredient (B) contains an average of only one or twohydrolyzable substituents per molecule and/or to increase crosslinkdensity of the reaction product prepared by condensation reaction of thecomposition. Generally, ingredient (C) is selected with functionalitythat can vary depending on the degree of crosslinking desired in thereaction product of the composition and such that the reaction productdoes not exhibit too much weight loss from by-products of thecondensation reaction. Generally, the selection of ingredient (C) ismade such that the composition remains sufficiently reactable to beuseful during storage for several months in a moisture impermeablepackage. Generally, ingredient (C) is selected such that thehydrolyzable substituents on ingredient (C) are reactive with ingredient(B). For example, when X in ingredient (B) is a hydroxyl group, then thehydrolyzable substituent for ingredient (C) may be a hydrogen atom, ahalogen atom; an amido group, an acyloxy groups, a hydrocarbonoxy group,an amino group, an aminoxy group, a mercapto group, an oximo group, aketoximo group, or an alkoxysilylhydrocarbylene group, or a combinationthereof. The exact amount of ingredient (C) can vary depending onfactors including the type of base polymer and crosslinker selected, thereactivity of the hydrolyzable substituents on the base polymer andcrosslinker, and the desired crosslink density of the reaction product.However, the amount of crosslinker may range from 0.5 to 100 parts basedon 100 parts by weight of ingredient (B).

Ingredient (C) may comprise a silane crosslinker having hydrolyzablegroups or partial or full hydrolysis products thereof. Ingredient (C)has an average, per molecule, of greater than two substituents reactivewith the hydrolyzable substituents on ingredient (B). Examples ofsuitable silane crosslinkers for ingredient (C) may have the generalformula (III) R⁸ _(k)Si(R⁹)_((4-k)), where each R⁸ is independently amonovalent hydrocarbon group such as an alkyl group; each R⁹ is ahydrolyzable substituent, which may be the same as X described above foringredient (B). Alternatively, each R⁹ may be, for example, a hydrogenatom, a halogen atom, an acetamido group, an acyloxy group such asacetoxy, an alkoxy group, an amido group, an amino group, an aminoxygroup, a hydroxyl group, an oximo group, a ketoximo group, or amethylacetamido group; and each instance of subscript k may be 0, 1, 2,or 3. For ingredient (C), subscript k has an average value greater than2. Alternatively, subscript k may have a value ranging from 3 to 4.Alternatively, each R⁹ may be independently selected from hydroxyl,alkoxy, acetoxy, amide, or oxime. Alternatively, ingredient (C) may beselected from an acyloxysilane, an alkoxysilane, a ketoximosilane, andan oximosilane.

Ingredient (C) may comprise an alkoxysilane exemplified by adialkoxysilane, such as a dialkyldialkoxysilane; a trialkoxysilane, suchas an alkyltrialkoxysilane; a tetraalkoxysilane; or partial or fullhydrolysis products thereof, or another combination thereof. Examples ofsuitable trialkoxysilanes include methyltrimethoxysilane,methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,isobutyltrimethoxysilane, isobutyltriethoxysilane, and a combinationthereof, and alternatively methyltrimethoxysilane. Examples of suitabletetraalkoxysilanes include tetraethoxysilane. The amount of thealkoxysilane that is used in the curable silicone composition may rangefrom 0.5 to 15, parts by weight per 100 parts by weight of ingredient(B).

Ingredient (C) may comprise an acyloxysilane, such as an acetoxysilane.Acetoxysilanes include a tetraacetoxysilane, an organotriacetoxysilane,a diorganodiacetoxysilane, or a combination thereof. The acetoxysilanemay contain alkyl groups such as methyl, ethyl, propyl, isopropyl,butyl, and tertiary butyl; alkenyl groups such as vinyl, allyl, orhexenyl; aryl groups such as phenyl, tolyl, or xylyl; aralkyl groupssuch as benzyl or 2-phenylethyl; and fluorinated alkyl groups such as3,3,3-trifluoropropyl. Exemplary acetoxysilanes include, but are notlimited to, tetraacetoxysilane, methyltriacetoxysilane,ethyltriacetoxysilane, vinyltriacetoxysilane, propyltriacetoxysilane,butyltriacetoxysilane, phenyltriacetoxysilane, octyltriacetoxysilane,dimethyldiacetoxysilane, phenylmethyldiacetoxysilane,vinylmethyldiacetoxysilane, diphenyl diacetoxysilane,tetraacetoxysilane, and combinations thereof. Alternatively, ingredient(C) may comprise organotriacetoxysilanes, for example mixturescomprising methyltriacetoxysilane and ethyltriacetoxysilane. The amountof the acetoxysilane that is used in the curable silicone compositionmay range from 0.5 to 15 parts by weight per 100 parts by weight ofingredient (B); alternatively 3 to 10 parts by weight of acetoxysilaneper 100 parts by weight of ingredient (B).

Examples of silanes suitable for ingredient (C) containing both alkoxyand acetoxy groups that may be used in the composition includemethyldiacetoxymethoxysilane, methylacetoxydimethoxysilane,vinyldiacetoxymethoxysilane, vinylacetoxydimethoxysilane,methyldiacetoxyethoxysilane, metylacetoxydiethoxysilane, andcombinations thereof.

Aminofunctional alkoxysilanes suitable for ingredient (C) areexemplified by H₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃,H₂N(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃,CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, and a combination thereof.

Suitable oximosilanes for ingredient (C) include alkyltrioximosilanessuch as methyltrioximosilane, ethyltrioximosilane, propyltrioximosilane,and butyltrioximosilane; alkoxytrioximosilanes such asmethoxytrioximosilane, ethoxytrioximosilane, and propoxytrioximosilane;or alkenyltrioximosilanes such as propenyltrioximosilane orbutenyltrioximosilane; alkenyloximosilanes such as vinyloximosilane;alkenylalkyldioximosilanes such as vinyl methyl dioximosilane, vinylethyldioximosilane, vinyl methyldioximosilane, orvinylethyldioximosilane; or combinations thereof.

Suitable ketoximosilanes for ingredient (C) include methyltris(dimethylketoximo)silane, methyl tris(methylethylketoximo)silane,methyl tris(methylpropylketoximo)silane, methyltris(methylisobutylketoximo)silane, ethyl tris(dimethylketoximo)silane,ethyl tris(methylethylketoximo)silane, ethyltris(methylpropylketoximo)silane, ethyltris(methylisobutylketoximo)silane, vinyl tris(dimethylketoximo)silane,vinyl tris(methylethylketoximo)silane, vinyltris(methylpropylketoximo)silane, vinyltris(methylisobutylketoximo)silane, tetrakis(dimethylketoximo)silane,tetrakis(methylethylketoximo)silane,tetrakis(methylpropylketoximo)silane,tetrakis(methylisobutylketoximo)silane,methylbis(dimethylketoximo)silane, methylbis(cyclohexylketoximo)silane,triethoxy(ethylmethylketoxime)silane,diethoxydi(ethylmethylketoxime)silane,ethoxytri(ethylmethylketoxime)silane,methylvinylbis(methylisobutylketoximo)silane, or a combination thereof.

Alternatively, ingredient (C) may be polymeric. For example, ingredient(C) may comprise a disilane such as bis(triethoxysilyl)hexane),1,4-bis[trimethoxysilyl(ethyl)]benzene, andbis[3-(triethoxysilyl)propyl]tetrasulfide

Ingredient (C) can be one single crosslinker or a combination comprisingtwo or more crosslinkers that differ in at least one of the followingproperties: hydrolyzable substituents and other organic groups bonded tosilicon, and when a polymeric crosslinker is used, siloxane units,structure, molecular weight, and sequence.

Ingredient (D) is a drying agent. The drying agent binds water fromvarious sources. For example, the drying agent may bind by-products ofthe condensation reaction, such as water and alcohols.

Examples of suitable adsorbents for ingredient (D) may be inorganicparticulates. The adsorbent may have a particle size of 10 micrometersor less, alternatively 5 micrometers or less. The adsorbent may haveaverage pore size sufficient to adsorb water and alcohols, for example10 Å (Angstroms) or less, alternatively 5 Å or less, and alternatively 3Å or less. Examples of adsorbents include zeolites such as chabasite,mordenite, and analcite; molecular sieves such as alkali metal aluminosilicates, silica gel, silica-magnesia gel, activated carbon, activatedalumina, calcium oxide, and combinations thereof.

Examples of commercially available drying agents include dry molecularsieves, such as 3 Å (Angstrom) molecular sieves, which are commerciallyavailable from Grace Davidson under the trademark SYLOSIV® and fromZeochem of Louisville, Ky., U.S.A. under the trade name PURMOL, and 4 Åmolecular sieves such as Doucil zeolite 4A available from Ineos Silicasof Warrington, England. Other useful molecular sieves include MOLSIVADSORBENT TYPE 13X, 3A, 4A, and 5A, all of which are commerciallyavailable from UOP of Illinois, U.S.A.; SILIPORITE NK 30AP and 65xP fromAtofina of Philadelphia, Pa., U.S.A.; and molecular sieves availablefrom W.R. Grace of Maryland, U.S.A.

Alternatively, the drying agent may bind the water and/or otherby-products by chemical means. An amount of a silane crosslinker addedto the composition (in addition to ingredient (C)) may function as achemical drying agent. Without wishing to be bound by theory, it isthought that the chemical drying agent may be added to the dry part of amultiple part composition to keep the composition free from water afterthe parts of the composition are mixed together. For example,alkoxysilanes suitable as drying agents include vinyltrimethoxysilane,vinyltriethoxysilane, and combinations thereof.

The amount of ingredient (D) depends on the specific drying agentselected. However, when ingredient (D) is a chemical drying agent, theamount may range from 0 parts to 5 parts, alternatively 0.1 parts to 0.5parts. Ingredient (D) may be one chemical drying agent. Alternatively,ingredient (D) may comprise two or more different chemical dryingagents.

Ingredient (E) is an extender and/or a plasticizer. An extendercomprising a non-functional polyorganosiloxane may be used in thecomposition. For example, the non-functional polyorganosiloxane maycomprise difunctional units of the formula R²² ₂SiO_(2/2) and terminalunits of the formula R²³ ₃SiD′-, where each R²² and each R²³ areindependently a monovalent organic group such as a monovalenthydrocarbon group exemplified by alkyl such as methyl, ethyl, propyl,and butyl; alkenyl such as vinyl, allyl, and hexenyl; aryl such asphenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such asphenylethyl; and D′ is an oxygen atom or a divalent group linking thesilicon atom of the terminal unit with another silicon atom (such asgroup D described above for ingredient (B)), alternatively D′ is anoxygen atom. Non-functional polyorganosiloxanes are known in the art andare commercially available. Suitable non-functional polyorganosiloxanesare exemplified by, but not limited to, polydimethylsiloxanes. Suchpolydimethylsiloxanes include DOW CORNING® 200 Fluids, which arecommercially available from Dow Corning Corporation of Midland, Mich.,U.S.A. and may have viscosity ranging from 50 cSt to 100,000 cSt,alternatively 50 cSt to 50,000 cSt, and alternatively 12,500 to 60,000cSt.

An organic plasticizer may be used in addition to, or instead of, thenon-functional polyorganosiloxane extender described above. Organicplasticizers are known in the art and are commercially available. Theorganic plasticizer may comprise a phthalate, a carboxylate, acarboxylic acid ester, an adipate or a combination thereof. The organicplasticizer may be selected from the group consisting of:bis(2-ethylhexyl) terephthalate;bis(2-ethylhexyl)-1,4-benzenedicarboxylate; 2-ethylhexylmethyl-1,4-benzenedicarboxylate; 1,2 cyclohexanedicarboxylic acid,dinonyl ester, branched and linear; bis(2-propylheptyl) phthalate;diisononyl adipate; and a combination thereof.

The organic plasticizer may have an average, per molecule, of at leastone group of formula

where R¹⁸ represents a hydrogen atom or a monovalent organic group.Alternatively, R¹⁸ may represent a branched or linear monovalenthydrocarbon group. The monovalent organic group may be a branched orlinear monovalent hydrocarbon group such as an alkyl group of 4 to 15carbon atoms, alternatively 9 to 12 carbon atoms. Suitable plasticizersmay be selected from the group consisting of adipates, carboxylates,phthalates, and a combination thereof.

Alternatively, the organic plasticizer may have an average, permolecule, of at least two groups of the formula above bonded to carbonatoms in a cyclic hydrocarbon. The organic plasticizer may have generalformula:

In this formula, group Z represents a carbocyclic group having 3 or morecarbon atoms, alternatively 3 to 15 carbon atoms. Subscript s may have avalue ranging from 1 to 12. Group Z may be saturated or aromatic. EachR²⁰ is independently a hydrogen atom or a branched or linear monovalentorganic group. The monovalent organic group for R¹⁹ may be an alkylgroup such as methyl, ethyl, or butyl. Alternatively, the monovalentorganic group for R²⁰ may be an ester functional group. Each R¹⁹ isindependently a branched or linear monovalent hydrocarbon group, such asan alkyl group of 4 to 15 carbon atoms.

Suitable organic plasticizers are known in the art and are commerciallyavailable. The plasticizer may comprise a phthalate, such as: a dialkylphthalate such as dibutyl phthalate (Eastman™ DBP Plasticizer), diheptylphthalate, di(2-ethylhexyl) phthalate, or diisodecyl phthalate (DIDP),bis(2-propylheptyl) phthalate (BASF Palatinol® DPHP), di(2-ethylhexyl)phthalate (Eastman™ DOP Plasticizer), dimethyl phthalate (Eastman™ DMPPlasticizer); diethyl phthalate (Eastman™ DMP Plasticizer); butyl benzylphthalate, and bis(2-ethylhexyl) terephthalate (Eastman™ 425Plasticizer); a dicarboxylate such as Benzyl, C7-C9 linear and branchedalkyl esters, 1,2, benzene dicarboxylic acid (Ferro SANTICIZER® 261A),1,2,4-benzenetricarboxylic acid (BASF Palatinol® TOTM-I),bis(2-ethylhexyl)-1,4-benzenedicarboxylate (Eastman™ 168 Plasticizer);2-ethylhexyl methyl-1,4-benzenedicarboxylate; 1,2cyclohexanedicarboxylic acid, dinonyl ester, branched and linear (BASFHexamoll *DINCH); diisononyl adipate; trimellitates such as trioctyltrimellitate (Eastman™ TOTM Plasticizer); triethylene glycolbis(2-ethylhexanoate) (Eastman™ TEG-EH Plasticizer); triacetin (Eastman™Triacetin); nonaromatic dibasic acid esters such as dioctyl adipate,bis(2-ethylhexyl) adipate (Eastman™ DOA Plasticizer and Eastman™ DOAPlasticizer, Kosher), di-2-ethylhexyladipate (BASF Plastomoll® DOA),dioctyl sebacate, dibutyl sebacate and diisodecyl succinate; aliphaticesters such as butyl oleate and methyl acetyl recinolate; phosphatessuch as tricresyl phosphate and tributyl phosphate; chlorinatedparaffins; hydrocarbon oils such as alkyldiphenyls and partiallyhydrogenated terphenyls; process oils; epoxy plasticizers such asepoxidized soybean oil and benzyl epoxystearate; tris(2-ethylhexyl)ester; a fatty acid ester; and a combination thereof. Examples of othersuitable plasticizers and their commercial sources include BASFPalamoll® 652 and Eastman 168 Xtreme™ Plasticizer.

Alternatively, a polymer plasticizer can be used. Examples of thepolymer plasticizer include alkenyl polymers obtained by polymerizingvinyl or allyl monomers by means of various methods; polyalkylene glycolesters such as diethylene glycol dibenzoate, triethylene glycoldibenzoate and pentaerythritol ester; polyester plasticizers obtainedfrom dibasic acids such as sebacic acid, adipic acid, azelaic acid andphthalic acid and dihydric alcohols such as ethylene glycol, diethyleneglycol, triethylene glycol, propylene glycol and dipropylene glycol;polyethers including polyether polyols each having a molecular weight ofnot less than 500 such as polyethylene glycol, polypropylene glycol andpolytetramethylene glycol, polystyrenes such as polystyrene andpoly-alpha-methylstyrene; and polybutadiene, polybutene,polyisobutylene, butadiene acrylonitrile, and polychloroprene.

When the organic plasticizer is present, the amount of the organicplasticizer may range from 5 to 150 parts by weight based on thecombined weights of all ingredients in the composition.

The polyorganosiloxane extenders and organic plasticizers describedabove for ingredient (E) may be used either each alone or incombinations of two or more thereof. A low molecular weight organicplasticizer and a higher molecular weight polymer plasticizer may beused in combination. The exact amount of ingredient (E) used in thecomposition can depend on various factors including the desired end useof the composition and the cured product thereof. However, the amount ofingredient (E) may range from 0.1% to 10 based on the combined weightsof all ingredients in the composition.

Ingredient (F) is a filler. The filler may comprise a reinforcingfiller, an extending filler, a conductive filler, or a combinationthereof. For example, the composition may optionally further compriseingredient (f1), a reinforcing filler, which when present may be addedin an amount ranging from 0.1% to 95%, alternatively 1% to 60%, based onthe weight of the composition. The exact amount of ingredient (f1)depends on various factors including the form of the reaction product ofthe composition and whether any other fillers are added. Examples ofsuitable reinforcing fillers include reinforcing silica fillers such asfume silica, silica aerogel, silica xerogel, and precipitated silica.Fumed silicas are known in the art and commercially available; e.g.,fumed silica sold under the name CAB-O-SIL by Cabot Corporation ofMassachusetts, U.S.A.

The composition may optionally further comprise ingredient (f2) anextending filler in an amount ranging from 0.1% to 95%, alternatively 1%to 60%, and alternatively 1% to 20%, based on the weight of thecomposition. Examples of extending fillers include crushed quartz,aluminum oxide, magnesium oxide, calcium carbonate such as precipitatedcalcium carbonate, zinc oxide, talc, diatomaceous earth, iron oxide,clays, mica, chalk, titanium dioxide, zirconia, sand, carbon black,graphite, or a combination thereof. Extending fillers are known in theart and commercially available; such as a ground silica sold under thename MIN-U-SIL by U.S. Silica of Berkeley Springs, W. Va. Suitableprecipitated calcium carbonates included Winnofil® SPM from Solvay andUltrapflex® and Ultrapflex® 100 from SMI.

The composition may optionally further comprise ingredient (f3) aconductive filler. Conductive fillers may be thermally conductive,electrically conductive, or both. Conductive fillers are known in theart and are exemplified by metal particulates (such as aluminum, copper,gold, nickel, silver, and combinations thereof); such metals coated onnonconductive substrates; metal oxides (such as aluminum oxide,beryllium oxide, magnesium oxide, zinc oxide, and combinations thereof),meltable fillers (e.g., solder), aluminum nitride, aluminum trihydrate,barium titanate, boron nitride, carbon fibers, diamond, graphite,magnesium hydroxide, onyx, silicon carbide, tungsten carbide, and acombination thereof.

Alternatively, other fillers may be added to the composition, the typeand amount depending on factors including the end use of the curedproduct of the composition. Examples of such other fillers includemagnetic particles such as ferrite; and dielectric particles such asfused glass microspheres, titania, and calcium carbonate.

The composition may optionally further comprise ingredient (G) atreating agent. The amount of ingredient (G) can vary depending onfactors such as the type of treating agent selected and the type andamount of particulates to be treated, and whether the particulates aretreated before being added to the composition, or whether theparticulates are treated in situ. However, ingredient (G) may be used inan amount ranging from 0.01 to 20%, alternatively 0.1% to 15%, andalternatively 0.5% to 5%, based on the weight of the composition.Particulates, such as the filler, the physical drying agent, certainflame retardants, certain pigments, and/or certain water release agents,when present, may optionally be surface treated with ingredient (G).Particulates may be treated with ingredient (G) before being added tothe composition, or in situ. Ingredient (G) may comprise analkoxysilane, an alkoxy-functional oligosiloxane, a cyclicpolyorganosiloxane, a hydroxyl-functional oligosiloxane such as adimethyl siloxane or methyl phenyl siloxane, or a fatty acid. Examplesof fatty acids include stearates such as calcium stearate.

Some representative organosilicon filler treating agents that can beused as ingredient (G) include compositions normally used to treatsilica fillers such as organochlorosilanes, organosiloxanes,organodisilazanes such as hexaalkyl disilazane, and organoalkoxysilanessuch as C₆H₁₃Si(OCH₃)₃, C₈H₁₇Si(OC₂H₅)₃, C₁₀H₂₁Si(OCH₃)₃,C₁₂H₂₅Si(OCH₃)₃, C₁₄H₂₉Si(OC₂H₅)₃, and C₆H₅CH₂CH₂Si(OCH₃)₃. Othertreating agents that can be used include alkylthiols, fatty acids,titanates, titanate coupling agents, zirconate coupling agents, andcombinations thereof.

Alternatively, ingredient (G) may comprise an alkoxysilane having theformula: R¹³ _(O)Si(OR¹⁴)_((4-p)), where subscript p may have a valueranging from 1 to 3, alternatively subscript p is 3. Each R¹³ isindependently a monovalent organic group, such as a monovalenthydrocarbon group of 1 to 50 carbon atoms, alternatively 8 to 30 carbonatoms, alternatively 8 to 18 carbon atoms. R¹³ is exemplified by alkylgroups such as hexyl, octyl, dodecyl, tetradecyl, hexadecyl, andoctadecyl; and aromatic groups such as benzyl and phenylethyl. R¹³ maybe saturated or unsaturated, and branched or unbranched. Alternatively,R¹³ may be saturated and unbranched.

Each R¹⁴ is independently a saturated hydrocarbon group of 1 to 4 carbonatoms, alternatively 1 to 2 carbon atoms. Ingredient (G) is exemplifiedby hexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane,dodecyltrimethoxysilane, tetradecyltrimethoxysilane,phenylethyltrimethoxysilane, octadecyltrimethoxysilane,octadecyltriethoxysilane, and combinations thereof.

Alkoxy-functional oligosiloxanes may also be used as treating agents.For example, suitable alkoxy-functional oligosiloxanes include those ofthe formula (R¹⁵O)_(q)Si(OSiR¹⁶ ₂R¹⁷)_((4-q)). In this formula,subscript q is 1, 2 or 3, alternatively subscript q is 3. Each R¹⁵ maybe an alkyl group. Each R¹⁶ may be an unsaturated monovalent hydrocarbongroup of 1 to 10 carbon atoms. Each R¹⁷ may be an unsaturated monovalenthydrocarbon group having at least 10 carbon atoms.

Certain particulates, such as metal fillers may be treated withalkylthiols such as octadecyl mercaptan; fatty acids such as oleic acidand stearic acid; and a combination thereof.

Other treating agents include alkenyl functional polyorganosiloxanes.Suitable alkenyl functional polyorganosiloxanes include, but are notlimited to:

where subscript r has a value up to 1,500.

Alternative, a polyorganosiloxane capable of hydrogen bonding is usefulas a treating agent. This strategy to treating surface of a filler takesadvantage of multiple hydrogen bonds, either clustered or dispersed orboth, as the means to tether the compatibilization moiety to the fillersurface. The polyorganosiloxane capable of hydrogen bonding has anaverage, per molecule, of at least one silicon-bonded group capable ofhydrogen bonding. The group may be selected from: an organic grouphaving multiple hydroxyl functionalities or an organic group having atleast one amino functional group. The polyorganosiloxane capable ofhydrogen bonding means that hydrogen bonding is the primary mode ofattachment for the polyorganosiloxane to a filler. Thepolyorganosiloxane may be incapable of forming covalent bonds with thefiller. The polyorganosiloxane may be free of condensable silyl groupse.g., silicon bonded alkoxy groups, silazanes, and silanols. Thepolyorganosiloxane capable of hydrogen bonding may be selected from thegroup consisting of a saccharide-siloxane polymer, an amino-functionalpolyorganosiloxane, and a combination thereof. Alternatively, thepolyorganosiloxane capable of hydrogen bonding may be asaccharide-siloxane polymer.

Ingredient (H) is a biocide. The amount of ingredient (H) can varydepending on factors including the type of biocide selected and thebenefit desired. However, the amount of ingredient (H) may range fromgreater than 0% to 5% based on the weight of all ingredients in thecomposition. Ingredient (H) is exemplified by (h1) a fungicide, (h2) anherbicide, (h3) a pesticide, (h4) an antimicrobial, or a combinationthereof.

Ingredient (h1) is a fungicide, for example, these include N-substitutedbenzimidazole carbamate, benzimidazolyl carbamate such as methyl2-benzimidazolylcarbamate, ethyl 2-benzimidazolylcarbamate, isopropyl2-benzimidazolylcarbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)-6-methylbenzimidazolyl]}carbamate,methylN-{2-[1-(N,N-dimethylcarbamoyl)-5-methylbenzimidazolyl]}carbamate,methyl N-{2-[1-(N-methylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-methylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, methylN-{2-[1-(N-methylcarbamoyl)-5-methylbenzimidazolyl]}carbamate, ethylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, ethylN-{2-[2-(N-methylcarbamoyl)benzimidazolyl]}carbamate, ethylN-{2-[1-(N,N-dimethylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, ethylN-{2-[1-(N-methylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, isopropylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, isopropylN-{2-[1-(N-methylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, methoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, methoxyethylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, methylN-{1-(N,N-dimethylcarbamoyloxy)benzimidazolyl]}carbamate, methylN-{2-[N-methylcarbamoyloxy)benzimidazolyl]}carbamate, methylN-{2-[1-(N-butylcarbamoyloxy)benzoimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-butylcarbamoyloxy)benzoimidazolyl]}carbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)-6-chlorobenzimidazolyl]}carbamate, andmethyl N-{2-[1-(N,N-dimethylcarbamoyl)-6-nitrobenzimidazolyl]}carbamate;10,10′-oxybisphenoxarsine (trade name: Vinyzene, OBPA),di-iodomethyl-para-tolylsulfone,benzothiophene-2-cyclohexylcarboxamide-S,S-dioxide,N-(fluordichloridemethylthio)phthalimide (trade names: Fluor-Folper,Preventol A3); methyl-benzimideazol-2-ylcarbamate (trade names:Carbendazim, Preventol BCM), Zinc-bis(2-pyridylthio-1-oxide) (zincpyrithion) 2-(4-thiazolyl)-benzimidazol, N-phenyl-iodpropargylcarbamate,N-octyl-4-isothiazolin-3-on,4,5-dichloride-2-n-octyl-4-isothiazolin-3-on,N-butyl-1,2-benzisothiazolin-3-on and/or Triazolyl-compounds, such astebuconazol in combination with zeolites containing silver.

Ingredient (h2) is an herbicide, for example, suitable herbicidesinclude amide herbicides such as allidochlorN,N-diallyl-2-chloroacetamide; CDEA 2-chloro-N,N-diethylacetamide;etnipromid(RS)-2-[5-(2,4-dichlorophenoxy)-2-nitrophenoxy]-N-ethylpropionamide;anilide herbicides such as cisanilidecis-2,5-dimethylpyrrolidine-1-carboxanilide; flufenacet4′-fluoro-N-isopropyl-2-[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yloxy]acetanilide;naproanilide (RS)-α-2-naphthoxypropionanilide; arylalanine herbicidessuch as benzoylprop N-benzoyl-N-(3,4-dichlorophenyl)-DL-alanine;flamprop-M N-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alanine;chloroacetanilide herbicides such as butachlorN-butoxymethyl-2-chloro-2,6′-diethylacetanilide; metazachlor2-chloro-N-(pyrazol-1-ylmethyl)acet-2′,6′-xylidide; prynachlor(RS)-2-chloro-N-(1-methylprop-2-ynyl)acetanilide; sulphonanilideherbicides such as cloransulam3-chloro-2-(5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidin-2-ylsulphonamido)benzoicacid; metosulam2′,6′-dichloro-5,7-dimethoxy-3′-methyl[1,2,4]triazolo[1,5-a]pyrimidine-2-sulphonanilide;antibiotic herbicides such as bilanafos4-[hydroxy(methyl)phosphinoyl]-L-homoalanyl-L-alanyl-L-alanine; benzoicacid herbicides such as chloramben 3-amino-2,5-dichlorobenzoic acid;2,3,6-TBA 2,3,6-trichlorobenzoic acid; pyrimidinyloxybenzoic acidherbicides such as bispyribac2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoic acid;pyrimidinylthiobenzoic acid herbicides such as pyrithiobac2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoic acid; phthalic acidherbicides such as chlorthal tetrachloroterephthalic acid; picolinicacid herbicides such as aminopyralid4-amino-3,6-dichloropyridine-2-carboxylic acid; quinolinecarboxylic acidherbicides such as quinclorac 3,7-dichloroquinoline-8-carboxylic acid;arsenical herbicides such as CMA calcium bis(hydrogen methylarsonate);MAMA ammonium hydrogen methylarsonate; sodium arsenite;benzoylcyclohexanedione herbicides such as mesotrione2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione; benzofuranylalkylsulphonate herbicides such as benfuresate2,3-dihydro-3,3-dimethylbenzofuran-5-yl ethanesulphonate; carbamateherbicides such as carboxazole methyl5-tert-butyl-1,2-oxazol-3-ylcarbamate; fenasulam methyl4-[2-(4-chloro-o-tolyloxy)acetamido]phenylsulphonylcarbamate;carbanilate herbicides such as BCPC (RS)-sec-butyl 3-chlorocarbanilate;desmedipham ethyl 3-phenylcarbamoyloxyphenylcarbamate; swep methyl3,4-dichlorocarbanilate; cyclohexene oxime herbicides such as butroxydim(RS)-(EZ)-5-(3-butyryl-2,4,6-trimethylphenyl)-2-(1-ethoxyiminopropyl)-3-hydroxycyclohex-2-en-1-one;tepraloxydim(RS)-(EZ)-2-{1-[(2E)-3-chloroallyloxyimino]propyl}-3-hydroxy-5-perhydropyran-4-ylcyclohex-2-en-1-one;cyclopropylisoxazole herbicides such as isoxachlortole4-chloro-2-mesylphenyl 5-cyclopropyl-1,2-oxazol-4-yl ketone;dicarboximide herbicides such as flumezin2-methyl-4-(α,α,α-trifluoro-m-tolyl)-1,2,4-oxadiazinane-3,5-dione;dinitroaniline herbicides such as ethalfluralinN-ethyl-α,α,α-trifluoro-N-(2-methylallyl)-2,6-dinitro-p-toluidine;prodiamine 5-dipropylamino-α,α,α-trifluoro-4,6-dinitro-o-toluidine;dinitrophenol herbicides such as dinoprop 4,6-dinitro-o-cymen-3-ol;etinofen α-ethoxy-4,6-dinitro-o-cresol; diphenyl ether herbicides suchas ethoxyfenO-[2-chloro-5-(2-chloro-α,α,α-trifluoro-p-tolyloxy)benzoyl]-L-lacticacid; nitrophenyl ether herbicides such as aclonifen2-chloro-6-nitro-3-phenoxyaniline; nitrofen 2,4-dichlorophenyl4-nitrophenyl ether; dithiocarbamate herbicides such as dazomet3,5-dimethyl-1,3,5-thiadiazinane-2-thione; halogenated aliphaticherbicides such as dalapon 2,2-dichloropropionic acid; chloroaceticacid; imidazolinone herbicides such as imazapyr(RS)-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid;inorganic herbicides such as disodium tetraborate decahydrate; sodiumazide; nitrile herbicides such as chloroxynil3,5-dichloro-4-hydroxybenzonitrile; ioxynil4-hydroxy-3,5-di-iodobenzonitrile; organophosphorus herbicides such asanilofos S-4-chloro-N-isopropylcarbaniloylmethyl O,O-dimethylphosphorodithioate; glufosinate4-[hydroxy(methyl)phosphinoyl]-DL-homoalanine; phenoxy herbicides suchas clomeprop (RS)-2-(2,4-dichloro-m-tolyloxy)propionanilide; fenteracol2-(2,4,5-trichlorophenoxy)ethanol; phenoxyacetic herbicides such as MCPA(4-chloro-2-methylphenoxy)acetic acid; phenoxybutyric herbicides such asMCPB 4-(4-chloro-o-tolyloxy)butyric acid; phenoxypropionic herbicidessuch as fenoprop (RS)-2-(2,4,5-trichlorophenoxy)propionic acid;aryloxyphenoxypropionic herbicides such as isoxapyrifop(RS)-2-[2[4-(3,5-dichloro-2-pyridyloxy)phenoxy]propionyl]isoxazolidine;phenylenediamine herbicides such as dinitramineN¹,N¹-diethyl-2,6-dinitro-4-trifluoromethyl-m-phenylenediamine,pyrazolyloxyacetophenone herbicides such as pyrazoxyfen2-[4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yloxy]acetophenone;pyrazolylphenyl herbicides such as pyraflufen2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenoxyaceticacid; pyridazine herbicides such as pyridafol6-chloro-3-phenylpyridazin-4-ol; pyridazinone herbicides such aschloridazon 5-amino-4-chloro-2-phenylpyridazin-3(2H)-one; oxapyrazon5-bromo-1,6-dihydro-6-oxo-1-phenylpyridazin-4-yloxamic acid; pyridineherbicides such as fluroxypyr4-amino-3,5-dichloro-6-fluoro-2-pyridyloxyacetic acid; thiazopyrmethyl2-difluoromethyl-5-(4,5-dihydro-1,3-thiazol-2-yl)-4-isobutyl-6-trifluoromethylnicotinate;pyrimidinediamine herbicides such as iprymidam6-chloro-N⁴-isopropylpyrimidine-2,4-diamine; quaternary ammoniumherbicides such as diethamquat1,1′-bis(diethylcarbamoylmethyl)-4,4′-bipyridinium; paraquat1,1′-dimethyl-4,4′-bipyridinium; thiocarbamate herbicides such ascycloate S-ethyl cyclohexyl(ethyl)thiocarbamate; tiocarbazil S-benzyldi-sec-butylthiocarbamate; thiocarbonate herbicides such as EXDO,O-diethyl dithiobis(thioformate); thiourea herbicides such asmethiuron 1,1-dimethyl-3-m-tolyl-2-thiourea; triazine herbicides such astriaziflam(RS)—N-[2-(3,5-dimethylphenoxy)-1-methylethyl]-6-(1-fluoro-1-methylethyl)-1,3,5-triazine-2,4-diamine;chlorotriazine herbicides such as cyprazine6-chloro-N²-cyclopropyl-N⁴-isopropyl-1,3,5-triazine-2,4-diamine;propazine 6-chloro-N²,N⁴-di-isopropyl-1,3,5-triazine-2,4-diamine;methoxytriazine herbicides such as prometonN²,N⁴-di-isopropyl-6-methoxy-1,3,5-triazine-2,4-diamine;methylthiotriazine herbicides such as cyanatryn2-(4-ethylamino-6-methylthio-1,3,5-triazin-2-ylamino)-2-methylpropionitrile;triazinone herbicides such as hexazinone3-cyclohexyl-6-dimethylamino-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione;triazole herbicides such as epronazN-ethyl-N-propyl-3-propylsulphonyl-1H-1,2,4-triazole-1-carboxamide;triazolone herbicides such as carfentrazone(RS)-2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-fluorophenyl}propionicacid; triazolopyrimidine herbicides such as florasulam2′,6′,8-trifluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulphonanilide;uracil herbicides such as flupropacil isopropyl2-chloro-5-(1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-trifluoromethylpyrimidin-1-yl)benzoate; urea herbicides such as cycluron3-cyclo-octyl-1,1-dimethylurea; monisouron1-(5-tert-butyl-1,2-oxazol-3-yl)-3-methylurea; phenylurea herbicidessuch as chloroxuron 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea;siduron 1-(2-methylcyclohexyl)-3-phenylurea; pyrimidinylsulphonylureaherbicides such as flazasulphuron1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-trifluoromethyl-2-pyridylsulphonyl)urea;pyrazosulphuron5-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulphamoyl]-1-methylpyrazole-4-carboxylicacid; triazinylsulphonylurea herbicides such as thifensulphuron3-(4-methoxy-6-methyl-1,3,5-triazin-2-ylcarbamoylsulphamoyl)thiophene-2-carboxylicacid; thiadiazolylurea herbicides such as tebuthiuron1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea; and/orunclassified herbicides such as chlorfenac (2,3,6-trichlorophenyl)aceticacid; methazole2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione; tritac(RS)-1-(2,3,6-trichlorobenzyloxy)propan-2-ol; 2,4-D, chlorimuron, andfenoxaprop; and combinations thereof.

Ingredient (h3) is a pesticide. Suitable pesticides are exemplified byatrazine, diazinon, and chlorpyrifos. For purposes of this application,pesticide includes insect repellents such as N,N-diethyl-meta-toluamideand pyrethroids such as pyrethrin.

Ingredient (h4) is an antimicrobial agent. Suitable antimicrobials arecommercially available, such as DOW CORNING® 5700 and DOW CORNING® 5772,which are from Dow Corning Corporation of Midland, Mich., U.S.A.

Alternatively, ingredient (H) may comprise a boron containing material,e.g., boric anhydride, borax, or disodium octaborate tetrahydrate; whichmay function as a pesticide, fungicide, and/or flame retardant.

Ingredient (J) is a flame retardant. Suitable flame retardants mayinclude, for example, carbon black, hydrated aluminum hydroxide, andsilicates such as wollastonite, platinum and platinum compounds.Alternatively, the flame retardant may be selected from halogen basedflame-retardants such as decabromodiphenyloxide, octabromordiphenyloxide, hexabromocyclododecane, decabromobiphenyl oxide,diphenyoxybenzene, ethylene bis-tetrabromophthalmide, pentabromoethylbenzene, pentabromobenzyl acrylate, tribromophenyl maleic imide,tetrabromobisphenyl A, bis-(tribromophenoxy) ethane,bis-(pentabromophenoxy) ethane, polydibomophenylene oxide,tribromophenylallyl ether, bis-dibromopropyl ether, tetrabromophthalicanhydride, dibromoneopentyl gycol, dibromoethyl dibromocyclohexane,pentabromodiphenyl oxide, tribromostyrene, pentabromochlorocyclohexane,tetrabromoxylene, hexabromocyclododecane, brominated polystyrene,tetradecabromodiphenoxybenzene, trifluoropropene and PVC. Alternatively,the flame retardant may be selected from phosphorus basedflame-retardants such as (2,3-dibromopropyl)-phosphate, phosphorus,cyclic phosphates, triaryl phosphate, bis-melaminium pentate,pentaerythritol bicyclic phosphate, dimethyl methyl phosphate, phosphineoxide diol, triphenyl phosphate, tris-(2-chloroethyl) phosphate,phosphate esters such as tricreyl, trixylenyl, isodecyl diphenyl,ethylhexyl diphenyl, phosphate salts of various amines such as ammoniumphosphate, trioctyl, tributyl or tris-butoxyethyl phosphate ester. Otherflame retardants may include tetraalkyl lead compounds such astetraethyl lead, iron pentacarbonyl, manganese methyl cyclopentadienyltricarbonyl, melamine and derivatives such as melamine salts, guanidine,dicyandiamide, ammonium sulphamate, alumina trihydrate, and magnesiumhydroxide alumina trihydrate.

The amount of flame retardant can vary depending on factors such as theflame retardant selected and whether solvent is present. However, theamount of flame retardant in the composition may range from greater than0% to 10% based on the combined weight of all ingredients in thecomposition.

Ingredient (K) is a surface modifier. Suitable surface modifiers areexemplified by (k1) an adhesion promoter or (k2) a release agent.Suitable adhesion promoters for ingredient (k1) may comprise atransition metal chelate, a hydrocarbonoxysilane such as analkoxysilane, a combination of an alkoxysilane and a hydroxy-functionalpolyorganosiloxane, an aminofunctional silane, or a combination thereof.Adhesion promoters are known in the art and may comprise silanes havingthe formula R²⁴ _(t)R²⁵ _(u)Si(OR²⁶)_(4-(t+u)) where each R²⁴ isindependently a monovalent organic group having at least 3 carbon atoms;R²⁵ contains at least one SiC bonded substituent having anadhesion-promoting group, such as amino, epoxy, mercapto or acrylategroups; subscript t has a value ranging from 0 to 2; subscript u iseither 1 or 2; and the sum of (t+u) is not greater than 3.Alternatively, the adhesion promoter may comprise a partial condensateof the above silane. Alternatively, the adhesion promoter may comprise acombination of an alkoxysilane and a hydroxy-functionalpolyorganosiloxane.

Alternatively, the adhesion promoter may comprise an unsaturated orepoxy-functional compound. The adhesion promoter may comprise anunsaturated or epoxy-functional alkoxysilane. For example, thefunctional alkoxysilane can have the formula R²⁷ _(v)Si(OR²⁸)_((4-v)),where subscript v is 1, 2, or 3, alternatively subscript v is 1. EachR²⁷ is independently a monovalent organic group with the proviso that atleast one R²⁷ is an unsaturated organic group or an epoxy-functionalorganic group. Epoxy-functional organic groups for R²⁷ are exemplifiedby 3-glycidoxypropyl and (epoxycyclohexyl)ethyl. Unsaturated organicgroups for R²⁷ are exemplified by 3-methacryloyloxypropyl,3-acryloyloxypropyl, and unsaturated monovalent hydrocarbon groups suchas vinyl, allyl, hexenyl, undecylenyl. Each R²⁸ is independently asaturated hydrocarbon group of 1 to 4 carbon atoms, alternatively 1 to 2carbon atoms. R²⁸ is exemplified by methyl, ethyl, propyl, and butyl.

Examples of suitable epoxy-functional alkoxysilanes include3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,(epoxycyclohexyl)ethyldimethoxysilane,(epoxycyclohexyl)ethyldiethoxysilane and combinations thereof. Examplesof suitable unsaturated alkoxysilanes include vinyltrimethoxysilane,allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane,undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane,3-methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyl triethoxysilane, and combinationsthereof.

Alternatively, the adhesion promoter may comprise an epoxy-functionalsiloxane such as a reaction product of a hydroxy-terminatedpolyorganosiloxane with an epoxy-functional alkoxysilane, as describedabove, or a physical blend of the hydroxy-terminated polyorganosiloxanewith the epoxy-functional alkoxysilane. The adhesion promoter maycomprise a combination of an epoxy-functional alkoxysilane and anepoxy-functional siloxane. For example, the adhesion promoter isexemplified by a mixture of 3-glycidoxypropyltrimethoxysilane and areaction product of hydroxy-terminated methylvinylsiloxane with3-glycidoxypropyltrimethoxysilane, or a mixture of3-glycidoxypropyltrimethoxysilane and a hydroxy-terminatedmethylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilaneand a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

Alternatively, the adhesion promoter may comprise an aminofunctionalsilane, such as an aminofunctional alkoxysilane exemplified byH₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃,H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, and a combination thereof.

Alternatively, the adhesion promoter may comprise a transition metalchelate. Suitable transition metal chelates include titanates,zirconates such as zirconium acetylacetonate, aluminum chelates such asaluminum acetylacetonate, and combinations thereof.

Ingredient (k2) is a release agent. Suitable release agents areexemplified by fluorinated compounds, such as fluoro-functionalsilicones, or fluoro-functional organic compounds.

Alternatively, the surface modifier for ingredient (K) may be used tochange the appearance of the surface of a reaction product of thecomposition. For example, surface modifier may be used to increase glossof the surface of a reaction product of the composition. Such a surfacemodifier may comprise a polydiorganosiloxane with alkyl and aryl groups.For example, DOW CORNING® 550 Fluid is a trimethylsiloxy-terminatedpoly(dimethyl/methylphenyl)siloxane with a viscosity of 125 cSt that iscommercially available from Dow Corning Corporation.

Alternatively, ingredient (K) may be a natural oil obtained from a plantor animal source, such as linseed oil, tung oil, soybean oil, castoroil, fish oil, hempseed oil, cottonseed oil, oiticica oil, and rapeseedoil.

The exact amount of ingredient (K) depends on various factors includingthe type of surface modifier selected as ingredient (K) and the end useof the composition and its reaction product. However, ingredient (K),when present, may be added to the composition in an amount ranging from0.01 to 50 weight parts based on the weight of the composition,alternatively 0.01 to 10 weight parts, and alternatively 0.01 to 5weight parts. Ingredient (K) may be one adhesion promoter.Alternatively, ingredient (K) may comprise two or more different surfacemodifiers that differ in at least one of the following properties:structure, viscosity, average molecular weight, polymer units, andsequence.

Chain lengtheners may include difunctional silanes and difunctionalsiloxanes, which extend the length of polyorganosiloxane chains beforecrosslinking occurs. Chain lengtheners may be used to reduce the modulusof elongation of the cured product. Chain lengtheners and crosslinkerscompete in their reactions with the hydrolyzable substituents iningredient (B). To achieve noticeable chain extension, the difunctionalsilane has substantially higher reactivity than the trifunctionalcrosslinker with which it is used. Suitable chain lengtheners includediamidosilanes such as dialkyldiacetamidosilanes oralkenylalkyldiacetamidosilanes, particularlymethylvinyldi(N-methylacetamido)silane, ordimethyldi(N-methylacetamido)silane, diacetoxysilanes such asdialkyldiacetoxysilanes or alkylalkenyldiacetoxysilanes, dieminosilanessuch as dialkyldiaminosilanes or alkylalkenyldiaminosilanes,dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilaneand α-aminoalkyldialkoxyalkylsilanes, polydialkylsiloxanes having adegree of polymerization of from 2 to 25 and having an average permolecule of at least two hydrolyzable groups, such as acetamido oracetoxy or amino or alkoxy or amido or ketoximo substituents, anddiketoximinosilanes such as dialkylkdiketoximinosilanes andalkylalkenyldiketoximinosilanes. Ingredient (L) may be one chainlengthener. Alternatively, ingredient (L) may comprise two or moredifferent chain lengtheners that differ in at least one of the followingproperties: structure, viscosity, average molecular weight, polymerunits, and sequence.

Ingredient (M) is and endblocker comprising an M unit, i.e., a siloxaneunit of formula R²⁹ ₃SiO_(1/2), where each R²⁹ independently representsa monovalent organic group unreactive ingredient (B), such as amonovalent hydrocarbon group. Ingredient (M) may comprisepolyorganosiloxanes endblocked on one terminal end by a triorganosilylgroup, e.g., (CH₃)₃SiO—, and on the other end by a hydroxyl group.Ingredient (M) may be a polydiorganosiloxane such as apolydimethylsiloxane. The polydiorganosiloxanes having both hydroxyl endgroups and triorganosilyl end groups, may have more than 50%,alternatively more than 75%, of the total end groups as hydroxyl groups.The amount of triorganosilyl group in the polydimethylsiloxane may beused to regulate the modulus of the reaction product prepared bycondensation reaction of the composition. Without wishing to be bound bytheory, it is thought that higher concentrations of triorganosilyl endgroups may provide a lower modulus in certain cured products. Ingredient(M) may be one endblocker. Alternatively, ingredient (M) may comprisetwo or more different endblockers that differ in at least one of thefollowing properties: structure, viscosity, average molecular weight,polymer units, and sequence.

Ingredient (N) is a non-reactive, elastomeric, organic polymer, i.e., anelastomeric organic polymer that does not react with ingredient (B).Ingredient (N) is compatible with ingredient (B), i.e., ingredient (N)does not form a two-phase system with ingredient (B). Ingredient (N) mayhave low gas and moisture permeability. Ingredient (N) may have Mnranging from 30,000 to 75,000. Alternatively, ingredient (N) may be ablend of a higher molecular weight, non-reactive, elastomeric, organicpolymer with a lower molecular weight, non-reactive, elastomeric,organic polymer. In this case, the higher molecular weight polymer mayhave Mn ranging from 100,000 to 600,000 and the lower molecular weightpolymer may have Mn ranging from 900 to 10,000, alternatively 900 to3,000. The value for the lower end of the range for Mn may be selectedsuch that ingredient (N) has compatibility with ingredient (B) and theother ingredients of the composition.

Ingredient (N) may comprise a polyisobutylene. Polyisobutylenes areknown in the art and are commercially available. Examples suitable foruse as ingredient (N) include polyisobutylenes marketed under thetrademark OPPANOL® by BASF Corporation of Germany.

Other polyisobutylenes include different Parleam grades such as highestmolecular weight hydrogenated polyisobutene PARLEAM® SV (POLYSYNLANE SV)from NOF CORPORATION Functional Chemicals & Polymers Div., Yebisu GardenPlace Tower, 20-3 Ebisu 4-chome, Shibuya-ku, Tokyo 150-6019, Japan(Kinematic Viscosity (98.9° C.) 4700). Other polyisobutylenes arecommercially available from ExxonMobil Chemical Co. of Baytown, Tex.,U.S.A. and include polyisobutylenes marketed under the trademarkVISTANEX®, such as MML-80, MML-100, MML-120, and MML-140. VISTANEX®polyisobutylenes are paraffinic hydrocarbon polymers, composed of long,straight-chain macromolecules containing only chain-end olefinic bonds.VISTANEX® MM polyisobutylenes have viscosity average molecular weightranging from 70,000 to 90,000. Lower molecular weight polyisobutylenesinclude VISTANEX® LM, such as LM-MS (viscosity average molecular weightranging from 8,700 to 10,000 also made by ExxonMobil Chemical Co.) andVISTANEX LM-MH (viscosity average molecular weight of 10,000 to 11,700)as well as Soltex PB-24 (Mn 950) and Indopol® H-100 (Mn 910) andIndopol® H-1200 (Mn 2100) from Amoco. Other polyisobutylenes aremarketed under the trademarks NAPVIS® and HYVIS® by BP Chemicals ofLondon, England. These polyisobutylenes include NAPVIS® 200, D10, andDE3; and HYVIS® 200. The NAPVIS® polyisobutylenes may have Mn rangingfrom 900 to 1300.

Alternatively, ingredient (N) may comprise butyl rubber. Alternatively,ingredient (N) may comprise a styrene-ethylene/butylene-styrene (SEBS)block copolymer, a styrene-ethylene/propylene-styrene (SEPS) blockcopolymer, or a combination thereof. SEBS and SEPS block copolymers areknown in the art and are commercially available as Kraton® G polymersfrom Kraton Polymers U.S. LLC of Houston, Tex., U.S.A., and as Septonpolymers from Kuraray America, Inc., New York, N.Y., U.S.A.Alternatively, ingredient (N) may comprise a polyolefin plastomer.Polyolefin plastomers are known in the art and are commerciallyavailable as AFFINITY® GA 1900 and AFFINITY® GA 1950 from Dow ChemicalCompany, Elastomers & Specialty Products Division, Midland, Mich.,U.S.A.

The amount of ingredient (N) may range from 0 parts to 50 parts,alternatively 10 parts to 40 parts, and alternatively 5 parts to 35parts, based on the weight of the composition. Ingredient (N) may be onenon-reactive, elastomeric, organic polymer. Alternatively, ingredient(N) may comprise two or more non-reactive, elastomeric, organic polymersthat differ in at least one of the following properties: structure,viscosity, average molecular weight, polymer units, and sequence.Alternatively, ingredient (N) may be added to the composition wheningredient (B) comprises a base polymer with an organic polymerbackbone.

Ingredient (O) is an anti-aging additive. The anti-aging additive maycomprise an antioxidant, a UV absorber, a UV stabilizer, a heatstabilizer, or a combination thereof. Suitable antioxidants are known inthe art and are commercially available. Suitable antioxidants includephenolic antioxidants and combinations of phenolic antioxidants withstabilizers. Phenolic antioxidants include fully sterically hinderedphenols and partially hindered phenols. Alternatively, the stabilizermay be a sterically hindered amine such as tetramethyl-piperidinederivatives. Suitable phenolic antioxidants include vitamin E andIRGANOX® 1010 from Ciba Specialty Chemicals, U.S.A. IRGANOX® 1010comprises pentaerythritoltetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate). Examples of UVabsorbers include phenol, 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-,branched and linear (TINUVIN® 571). Examples of UV stabilizers includebis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate; methyl1,2,2,6,6-pentamethyl-4-piperidyl/sebacate; and a combination thereof(TINUVIN® 272). These and other TINUVIN® additives, such as TINUVIN® 765are commercially available from Ciba Specialty Chemicals of Tarrytown,N.Y., U.S.A. Other UV and light stabilizers are commercially available,and are exemplified by LowLite from Chemtura, OnCap from PolyOne, andLight Stabilizer 210 from E. I. du Pont de Nemours and Company ofDelaware, U.S.A. Oligomeric (higher molecular weight) stabilizers mayalternatively be used, for example, to minimize potential for migrationof the stabilizer out of the composition or the cured product thereof.An example of an oligomeric antioxidant stabilizer (specifically,hindered amine light stabilizer (HALS)) is Ciba TINUVIN® 622, which is adimethylester of butanedioic acid copolymerized with4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol. Heat stabilizers mayinclude iron oxides and carbon blacks, iron carboxylate salts, ceriumhydrate, barium zirconate, cerium and zirconium octoates, andporphyrins.

The amount of ingredient (O) depends on various factors including thespecific anti-aging additive selected and the anti-aging benefitdesired. However, the amount of ingredient (O) may range from 0 to 5weight %, alternatively 0.1% to 4%, and alternatively 0.5% to 3%, basedon the weight of the composition. Ingredient (O) may be one anti-agingadditive. Alternatively, ingredient (O) may comprise two or moredifferent anti-aging additives.

Ingredient (P) is a water release agent that releases water over anapplication temperature range. Ingredient (P) is selected such thatingredient (P) contains an amount of water sufficient to partially orfully react the composition and such that ingredient (P) releases thesufficient amount of water when exposed for a sufficient amount of timeto a use temperature (i.e., a temperature at which the composition isused). However, ingredient (P) binds the water sufficiently to preventtoo much water from being released during the method for making thecomposition and during storage of the composition. For example,ingredient (P) binds the water sufficiently during compounding of thecomposition such that sufficient water is available for condensationreaction of the composition during or after the application process inwhich the composition is used. This “controlled release” property alsomay provide the benefit of ensuring that not too much water is releasedtoo rapidly during the application process, since this may causebubbling or voiding in the reaction product formed by condensationreaction of the composition. Precipitated calcium carbonate may be usedas ingredient (P) when the application temperature ranges from 80° C. to120° C., alternatively 90° C. to 110° C., and alternatively 90° C. to100° C. However, when the composition is prepared on a continuous (e.g.,twin-screw) compounder, the ingredients may be compounded at atemperature 20° C. to 30° C. above the application temperature range fora short amount of time. Therefore, ingredient (P) is selected to ensurethat not all of the water content is released during compounding;however ingredient (P) releases a sufficient amount of water forcondensation reaction of the composition when exposed to the applicationtemperature range for a sufficient period of time.

Examples of suitable water release agents are exemplified by metal salthydrates, hydrated molecular sieves, and precipitated calcium carbonate,which is available from Solvay under the trademark WINNOFIL® SPM. Thewater release agent selected can depend on various factors including theother ingredients selected for the composition, including catalyst typeand amount; and the process conditions during compounding, packaging,and application. In a twin-screw compounder, residence time may be lessthan a few minutes, typically less than 1 to 2 minutes. The ingredientsare heated rapidly because the surface area/volume ratio in the barrelsand along the screw is high and heat is induced by shearing theingredients. How much water is removed from ingredient (P) depends onthe water binding capabilities, the temperature, the exposure time(duration), and the level of vacuum used to strip the compositionpassing through the compounder. Without wishing to be bound by theory,it is thought that with a twin screw compounding temperature of 120° C.there would remain enough water on the precipitated CaCO₃ to cause thecomposition to react by condensation reaction over a period of 1 to 2weeks at room temperature when the composition has been applied at 90°C.

A water release agent may be added to the composition, for example, whenthe base polymer has low water permeability (e.g., when the base polymerhas an organic polymer backbone) and/or the amount of ingredient (P) inthe composition depends on various factors including the selection ofingredients (A), (B) and (C) and whether any additional ingredients arepresent, however the amount of ingredient (P) may range from 5 to 30parts based on the weight of the composition.

Without wishing to be bound by theory, it is thought when thecomposition is heated to the application temperature, the heat wouldliberate the water, and the water would react with the hydrolyzablegroups on ingredient (B) to react the composition. By-products such asalcohols and/or water left in the composition may be bound by a dryingagent, thereby allowing the condensation reaction (which is anequilibrium reaction) to proceed toward completion.

Ingredient (Q) is a pigment. For purposes of this application, the term‘pigment’ includes any ingredient used to impart color to a reactionproduct of a composition described herein. The amount of pigment dependson various factors including the type of pigment selected and thedesired degree of coloration of the reaction product. For example, thecomposition may comprise 0 to 20%, alternatively 0.001% to 5%, of apigment based on the weight of all ingredients in the composition.

Examples of suitable pigments include indigo, titanium dioxide Stan-Tone50SP01 Green (which is commercially available from PolyOne) and carbonblack. Representative, non-limiting examples of carbon black includeShawinigan Acetylene black, which is commercially available from ChevronPhillips Chemical Company LP; SUPERJET® Carbon Black (LB-1011) suppliedby Elementis Pigments Inc., of Fairview Heights, Ill. U.S.A.; SR 511supplied by Sid Richardson Carbon Co, of Akron, Ohio U.S.A.; and N330,N550, N762, N990 (from Degussa Engineered Carbons of Parsippany, N.J.,U.S.A.).

The composition may optionally further comprise up to 5%, alternatively1% to 2 based on the weight of the composition of ingredient (R) arheological additive for modifying rheology of the composition.Rheological additives are known in the art and are commerciallyavailable. Examples include polyamides, Polyvest, which is commerciallyavailable from Evonik, Disparlon from King Industries, Kevlar Fibre Pulpfrom Du Pont, Rheospan from Nanocor, and Ircogel from Lubrizol. Othersuitable rheological additives include polyamide waxes; hydrogenatedcastor oil derivatives; and metal soaps such as calcium stearate,aluminum stearate and barium stearate, and combinations thereof.

Alternatively, ingredient (R) may comprise a microcrystalline wax thatis a solid at 25° C. (wax). The melting point may be selected such thatthe wax has a melting point at the low end of the desired applicationtemperature range. Without wishing to be bound by theory, it is thoughtthat ingredient (R) acts as a process aid that improves flow propertieswhile allowing rapid green strength development (i.e., a strong increasein viscosity, corresponding to increase in the load carrying capabilityof a seal prepared from the composition, with a temperature drop) uponcooling the composition a few degrees, for example, after thecomposition is applied to a substrate. Without wishing to be bound bytheory, it is thought that incorporation of wax may also facilitateincorporation of fillers, compounding and de-airing (during productionof the composition), and mixing (static or dynamic mixing duringapplication of parts of a multiple-part composition). It is thought thatthe wax, when molten, serves as a process aid, substantially easing theincorporation of filler in the composition during compounding, thecompounding process itself, as well as in during a de-airing step, ifused. The wax, with a melt temperature below 100° C., may facilitatemixing of the parts of a multiple part composition before application,even in a simple static mixer. The wax may also facilitate applicationof the composition at temperatures ranging from 80° C. to 110° C.,alternatively 90° C. to 100° C. with good rheology.

Waxes suitable for use as ingredient (R) may be non-polar hydrocarbons.The waxes may have branched structures, cyclic structures, orcombinations thereof. For example, petroleum microcrystalline waxes areavailable from Strahl & Pitsch, Inc., of West Babylon, N.Y., U.S.A. andinclude SP 96 (melting point ranging from 62° C. to 69° C.), SP 18(melting point ranging from 73° C. to 80° C.), SP 19 (melting pointranging from 76° C. to 83° C.), SP 26 (melting point ranging from 76° C.to 83° C.), SP 60 (melting point ranging from 79° C. to 85° C.), SP 617(melting point ranging from 88° C. to 93° C.), SP 89 (melting pointranging from 90° C. to 95° C.), and SP 624 (melting point ranging from90° C. to 95° C.). Other petroleum microcrystalline waxes include waxesmarketed under the trademark Multiwax® by Crompton Corporation ofPetrolia, Pa., U.S.A. These waxes include 180-W, which comprisessaturated branched and cyclic non-polar hydrocarbons and has meltingpoint ranging from 79° C. to 87° C.; Multiwax® W-445, which comprisessaturated branched and cyclic non-polar hydrocarbons, and has meltingpoint ranging from 76° C. to 83° C.; and Multiwax® W-835, whichcomprises saturated branched and cyclic non-polar hydrocarbons, and hasmelting point ranging from 73° C. to 80° C.

The amount of ingredient (R) depends on various factors including thespecific rheological additive selected and the selections of the otheringredients of the composition. However, the amount of ingredient (R)may range from 0 parts to 20 parts, alternatively 1 part to 15 parts,and alternatively 1 part to 5 parts based on the weight of thecomposition. Ingredient (R) may be one rheological additive.Alternatively, ingredient (R) may comprise two or more differentrheological additives.

A vehicle (e.g., a solvent and/or diluent) may be used in thecomposition. Vehicle may facilitate flow of the composition andintroduction of certain ingredients, such as silicone resin. Vehiclesused herein are those that help fluidize the ingredients of thecomposition but essentially do not react with any of these ingredients.Vehicle may be selected based on solubility the ingredients in thecomposition and volatility. The solubility refers to the vehicle beingsufficient to dissolve and/or disperse ingredients of the composition.Volatility refers to vapor pressure of the vehicle. If the vehicle istoo volatile (having too high vapor pressure) bubbles may form in thecomposition at the application temperature, and the bubbles may causecracks or otherwise weaken or detrimentally affect properties of thecured product. However, if the vehicle is not volatile enough (too lowvapor pressure) the vehicle may remain as a plasticizer in the reactionproduct of the composition, or the amount of time for the reactionproduct to develop physical properties may be longer than desired.

Suitable vehicles include polyorganosiloxanes with suitable vaporpressures, such as hexamethyldisiloxane, octamethyltrisiloxane,hexamethylcyclotrisiloxane, and other low molecular weightpolyorganosiloxanes, such as 0.5 to 1.5 centiStoke (cSt) Dow Corning®200 Fluids and DOW CORNING® OS FLUIDS, which are commercially availablefrom Dow Corning Corporation of Midland, Mich., U.S.A.

Alternatively, the vehicle may be an organic solvent. The organicsolvent can be an alcohol such as methanol, ethanol, isopropanol,butanol, or n-propanol; a ketone such as acetone, methylethyl ketone, ormethyl isobutyl ketone; an aromatic hydrocarbon such as benzene,toluene, or xylene; an aliphatic hydrocarbon such as heptane, hexane, oroctane; a glycol ether such as propylene glycol methyl ether,dipropylene glycol methyl ether, propylene glycol n-butyl ether,propylene glycol n-propyl ether, or ethylene glycol n-butyl ether, ahalogenated hydrocarbon such as dichloromethane, 1,1,1-trichloroethaneor methylene chloride; chloroform; dimethyl sulfoxide; dimethylformamide, acetonitrile; tetrahydrofuran; white spirits; mineralspirits; naphtha; n-methyl pyrrolidone; or a combination thereof.

The amount of vehicle can depend on various factors including the typeof vehicle selected and the amount and type of other ingredientsselected for the composition. However, the amount of vehicle may rangefrom 1% to 99%, alternatively 2% to 50%, based on the weight of thecomposition.

The composition may optionally further comprise ingredient (T) atackifying agent. The tackifying agent may comprise an aliphatichydrocarbon resin such as a hydrogenated polyolefin having 6 to 20carbon atoms, a hydrogenated terpene resin, a rosin ester, ahydrogenated rosin glycerol ester, or a combination thereof. Tackifyingagents are commercially available. Aliphatic hydrocarbon resins areexemplified by ESCOREZ 1102, 1304, 1310, 1315, and 5600 from ExxonChemical and Eastotac resins from Eastman, such as Eastotac H-100 havinga ring and ball softening point of 100° C., Eastotac H-115E having aring and ball softening point of 115° C., and Eastotac H-130L having aring and ball softening point of 130° C. Hydrogenated terpene resins areexemplified by Arkon P 100 from Arakawa Chemicals and Wingtack 95 fromGoodyear. Hydrogenated rosin glycerol esters are exemplified byStaybelite Ester 10 and Foral from Hercules. Examples of commerciallyavailable polyterpenes include Piccolyte A125 from Hercules. Examples ofaliphatic/aromatic or cycloaliphatic/aromatic resins include ECR 149B orECR 179A from Exxon Chemical. Alternatively, a solid tackifying agent(i.e., a tackifying agent having a ring and ball softening point above25° C.), may be added. Suitable tackifying agents include any compatibleresins or mixtures thereof such as (1) natural or modified rosins such,for example, as gum rosin, wood rosin, tall-oil rosin, distilled rosin,hydrogenated rosin, dimerized rosin, and polymerized rosin; (2) glyceroland pentaerythritol esters of natural or modified rosins, such, forexample as the glycerol ester of pale, wood rosin, the glycerol ester ofhydrogenated rosin, the glycerol ester of polymerized rosin, thepentaerythritol ester of hydrogenated rosin, and the phenolic-modifiedpentaerythritol ester of rosin; (3) copolymers and terpolymers ofnatural terpenes, e.g., styrene/terpene and alpha methylstyrene/terpene; (4) polyterpene resins having a softening point, asdetermined by ASTM method E28,58T, ranging from 60° C. to 150° C.; thelatter polyterpene resins generally resulting from the polymerization ofterpene hydrocarbons, such as the bicyclic monoterpene known as pinene,in the presence of Friedel-Crafts catalysts at moderately lowtemperatures; also included are the hydrogenated polyterpene resins; (5)phenolic modified terpene resins and hydrogenated derivatives thereof,for example, as the resin product resulting from the condensation, in anacidic medium, of a bicyclic terpene and phenol; (6) aliphatic petroleumhydrocarbon resins having a ring and ball softening point ranging from60° C. to 135° C.; the latter resins resulting from the polymerizationof monomers consisting of primarily of olefins and diolefins; alsoincluded are the hydrogenated aliphatic petroleum hydrocarbon resins;(7) alicyclic petroleum hydrocarbon resins and the hydrogenatedderivatives thereof; and (8) aliphatic/aromatic orcycloaliphatic/aromatic copolymers and their hydrogenated derivatives.The amount of tackifying agent depends on various factors including thespecific tackifying agent selected and the selection the otheringredients in the composition. However, the amount of tackifying agentmay range from 0 parts to 20 parts based on the weight of thecomposition.

The composition may optionally further comprise ingredient (U), acorrosion inhibitor. Examples of suitable corrosion inhibitors includebenzotriazole, mercaptabenzotriazole and commercially availablecorrosion inhibitors such as 2,5-dimercapto-1,3,4-thiadiazole derivative(CUVAN® 826) and alkylthiadiazole (CUVAN® 484) from R. T. Vanderbilt ofNorwalk, Conn., U.S.A. When present, the amount of ingredient (U) mayrange from 0.05% to 0.5% based on the weight of the composition.

When selecting ingredients for the composition described above, theremay be overlap between types of ingredients because certain ingredientsdescribed herein may have more than one function. For example, certainalkoxysilanes may be useful as filler treating agents and as adhesionpromoters, certain fatty acid esters may be useful as plasticizers andmay also be useful as filler treating agents, carbon black may be usefulas a pigment, a flame retardant, and/or a filler, and nonreactivepolydiorganosiloxanes such as polydimethylsiloxanes may be useful asextenders and as solvents.

The composition described above may be prepared as a one partcomposition, for example, by combining all ingredients by any convenientmeans, such as mixing. For example, a one-part composition may be madeby optionally combining (e.g., premixing) the base polymer (B) and anextender (E) and mixing the resulting extended base polymer with all orpart of the filler (F), and mixing this with a pre-mix comprising thecrosslinker (C) and ingredient (A). Other additives such as (O) theanti-aging additive and (Q) the pigment may be added to the mixture atany desired stage. A final mixing step may be performed undersubstantially anhydrous conditions, and the resulting compositions aregenerally stored under substantially anhydrous conditions, for examplein sealed containers, until ready for use.

Alternatively, the composition may be prepared as a multiple part (e.g.,2 part) composition when a crosslinker is present. In this instance thecatalyst and crosslinker are stored in separate parts, and the parts arecombined shortly before use of the composition. For example, a two partcurable composition may be prepared by combining ingredients comprising(B) and (C) to form a first (curing agent) part by any convenient meanssuch as mixing. A second (base) part may be prepared by combiningingredients comprising (A) and (B) by any convenient means such asmixing. The ingredients may be combined at ambient or elevatedtemperature and under ambient or anhydrous conditions, depending onvarious factors including whether a one part or multiple partcomposition is selected. The base part and curing agent part may becombined by any convenient means, such as mixing, shortly before use.The base part and curing agent part may be combined in relative amountsof base: curing agent ranging from 1:1 to 10:1.

The equipment used for mixing the ingredients is not specificallyrestricted. Examples of suitable mixing equipment may be selecteddepending on the type and amount of each ingredient selected. Forexample, agitated batch kettles may be used for relatively low viscositycompositions, such as compositions that would react to form gums orgels. Alternatively, continuous compounding equipment, e.g., extruderssuch as twin screw extruders, may be used for more viscous compositionsand compositions containing relatively high amounts of particulates.Exemplary methods that can be used to prepare the compositions describedherein include those disclosed in, for example, U.S. Patent PublicationsUS 2009/0291238 and US 2008/0300358.

These compositions made as described above may be stable when the storedin containers that protect the compositions from exposure to moisture,but these compositions may react via condensation reaction when exposedto atmospheric moisture. Alternatively, when a low permeabilitycomposition is formulated, the composition may cure to form a curedproduct when moisture is released from a water release agent.

Compositions prepared as described above, and the reaction productsthereof, have various uses. The ingredients described above may be usedto prepare various types of composition comprising ingredients (A) and(B). The composition may further comprise one or more of the additionalingredients described above, depending on the type of composition andthe desired end use of the composition and/or the reaction product ofthe composition. For example, the ingredients and methods describedabove may be used for chain extension processes to increase viscosity ofthe base polymer and/or form a gum, for example, when the base polymerhas an average of one to two hydrolyzable groups per molecule.Alternatively, the ingredients and methods described above may be usedto formulate curable compositions, for example, when the base polymerhas two or more hydrolyzable groups per molecule and/or a crosslinker ispresent in the composition. The compositions described herein may bereacted by condensation reaction by exposure to moisture. For example,the compositions may react via condensation reaction when exposed toatmospheric moisture. Alternatively, the composition react moisture isreleased from a water release agent, when a water release agent ispresent. Each composition described herein reacts to form a reactionproduct. The reaction product may have a form selected from a gum, agel, a rubber, or a resin.

EXAMPLES

These examples are intended to illustrate some embodiments of theinvention and should not be interpreted as limiting the scope of theinvention set forth in the claims. Reference examples should not bedeemed to be prior art unless so indicated. The following ingredientswere used in the examples below. Diethyl zinc (“ZnEt2”) and diphenylzinc (“ZnPh2”) were purchased from Sigma-Aldrich of St. Louis, Mo.,U.S.A. Zinc octanoate (“ZnOCT2”) was purchased from City Chemicals LLCof West Haven, Conn., U.S.A. The crosslinker, n-butyltrimethoxysilane(“n-BuSi(O-Me)₃”), was purchased from Gelest, Inc. of Morrisville, Pa.,U.S.A. The base polymer, which was a silanol terminatedpolydimethylsiloxane having a viscosity of 90 to 120 cSt and numberaverage molecular weight, Mw, of 4200 (“PDMS 1”), was also purchasedfrom Gelest, Inc.

Example 1 Formation of Metal-Ligand Complexes

Precursor solutions were prepared by mixing a Zn precursor describedabove at a 0.025 M concentration with toluene. The precursor solutionswere colorless. Solutions of each ligand shown above in Table 1 wereprepared by mixing each ligand at a 0.025 M concentration with toluene.

Each ligand solution prepared above was dispensed into pre-weighted 1milliliter (mL) vials. Either 24 microliters (μL) of solution(corresponding to 0.6 micromole, μmol, of ligand) or 48 μL of solution(corresponding to 1.2 μmol of ligand) was used in each vial. Toluene inthe vial was removed by leaving the vials uncapped in a box with flowingnitrogen overnight.

To each vial containing ligand (now without solvent) was added 24 μL ofa precursor solution prepared as described above (corresponding to 0.6μmol of precursor) to form a metal-ligand combination solution. The vialcontaining the metal-ligand combination solution was shaken at 60revolutions per minute (rpm) at either 25° C. or 75° C. to form ametal-ligand complex.

Example 2 Condensation Reaction

Upon completion of the complexation reaction described above (in Example1), 210 milligrams (mg) of PDMS 1 (corresponding to 235.7 μL or 50 μmol)and 17.8 mg of n-BuSi(O-Me)₃ (corresponding to 19.1 or 100 μmol) wereinjected into each vial containing a metal-ligand complex in a dry box.More toluene was then added to ensure total volume in each vial was 325Example 2 samples were prepared in this manner. Negative control sampleswere also prepared using the precursor described above, but no ligand.In the negative control samples, 210 mg of PDMS 1, 17.8 mg ofn-BuSi(O-Me)₃, toluene (a sufficient amount to reach a total amount of325 μL) were injected into a vial with the precursor. Additionalnegative control samples were also prepared using the ligands describedabove in Table 1, but no precursor. In these additional negative controlsamples, 210 mg of PDMS 1, 17.8 mg of n-BuSi(O-Me)₃, toluene (asufficient amount to reach a total amount of 325 μL) were injected intoa vial with the ligand.

The resulting vials containing compositions were taken out of the drybox into a hood and stirred for 1 min with vigorous stirring (severalhundred rpm to homogenize each composition). The vials were then eachcovered with a perforated plate and placed into a humidity ovenmaintained at 30° C. with a relative humidity level (RH) of 95%.

After 48 hours in the humidity oven, the vials were removed from thehumidity oven, and visual viscosity observations were recorded. The 48hour visual viscosity measurements were determined by side to sidevisual comparison of the samples with vials containing differentviscosity reference standards. The measurements were performed 48 hoursafter the samples were first exposed to moisture. The visual viscositymeasurement value of each sample was assigned based on the vial of thereference standard it most closely matched. The reference standards wereDOW CORNING® 200 fluids (“200 Fluid”) of different viscosities, whichwere commercially available from Dow Corning Corporation of Midland,Mich., U.S.A. The visual viscosity description and standard to which itcorresponded are shown below in Table 2. A value of 0 or 1 indicatedthat the sample did not exhibit condensation reaction in the 48 hours. Avalue of 2 to 5 indicated that condensation reaction increasinglyoccurred. Replicate experiments were subject to normal variation due tovarious factors, such as the operator performing the visual viscositymeasurement and whether the replicate experiments were performed atdifferent times.

TABLE 2 Visual Viscosity Measurement 0—No Change  50 cSt 200 Fluid1—Slightly viscous  500 cSt 200 Fluid 2—Viscous 1000 cSt 200 Fluid3—Very viscous 5000 cSt 200 Fluid 4—Extremely viscous 50000 cSt 200Fluid  5—No flow No flow observed

Table 3 showed the ligand, metal precursor Ligand: Metal Ratio, reactionconditions (time and temperature), and results (48 Hour Visual Viscosityand Appearance) for the samples prepared using the ligands in Table 1.

TABLE 3 Examples 48 Hour Ligand: Complexation Visual Ligand MetalTemperature Complexation Viscosity Precursor Ligand μmoles Ratio (degC.) Time (min) Appearance Value ZnEt2 None 0 0 25 60 C 1 ZnEt2 None 0 075 30 C 1 ZnEt2 None 0 0 none 0 C 1 ZnOCT2 None 0 0 25 60 C 1 ZnOCT2None 0 0 75 30 C 1 ZnOCT2 None 0 0 none 0 C 1 ZnPh2 None 0 0 none 0 C 1ZnEt2 1 0.6 1 25 60 H 1 ZnEt2 1 0.6 1 75 30 H 1 ZnOCT2 1 0.6 1 25 60 H 3ZnOCT2 1 0.6 1 75 30 H 2 ZnEt2 2 0.6 1 25 60 H 2 ZnEt2 2 0.6 1 75 30 H 2ZnOCT2 2 0.6 1 25 60 H 1 ZnOCT2 2 0.6 1 75 30 H 1

In Table 3, values for appearance are defined as follows, ‘H’ meanshazy, and ‘C’ means clear. For each ligand in Table 3, a negativecontrol sample was prepared in which the ligand was tested according tothe method of Example 2, except using no precursor. In each instance,the 48 Hour Visual Viscosity Value was 1.

Example 3 Formation of Metal-Ligand Complexes

A precursor solution was prepared by mixing Zinc 2-ethylhexanoate at a0.025 M concentration with toluene. The precursor solutions werecolorless. Solutions of each ligand shown in Table 6 by mixing theligand at a 0.025 M concentration with toluene.

Each ligand solution prepared above was dispensed into a pre-weighted 8milliliter (mL) vial. Either 240 microliters (4) of solution(corresponding to 6 micromole, of ligand) or 480 μL of solution(corresponding to 12 μmol of ligand) was used in each vial. Toluene inthe vial was removed by leaving the vials uncapped in a box with flowingnitrogen overnight.

To each vial containing ligand (now without solvent) was added 240 μL ofthe precursor solution prepared as described above (corresponding to 6μmol of precursor) to form a metal-ligand combination solution. The vialcontaining the metal-ligand combination solution was shaken at 60revolutions per minute (rpm) at either 25° C. or 75° C. to form ametal-ligand complex.

Example 4 Condensation Reaction

Upon completion of the complexation reaction described above (in Example3), 2037 milligrams (mg) of PDMS 1 and 129.9 mg ofmethyltrimethoxysilane (MTM) were injected into each vial containing ametal-ligand complex in a dry box. More toluene was then added to ensuretotal volume in each vial was 3 mL. Example 4 samples were prepared inthis manner. Negative control samples were also prepared using theprecursor described above, but no ligand. In the negative controlsamples, 2037 mg of PDMS 1, 129.9 mg of MTM, toluene (a sufficientamount to reach a total amount of 3 mL) were injected into a vial withthe precursor. Additional negative control samples were also preparedusing the ligands described above in Table 1, but no precursor. In theseadditional negative control samples, 2037 mg of PDMS 1, 129.9 mg of MTM,toluene (a sufficient amount to reach a total amount of 3 mL) wereinjected into a vial with the ligand.

The resulting vials containing compositions were taken out of the drybox into a hood and stirred for 1 min with vigorous stirring (severalhundred rpm to homogenize each composition). The vials were then eachcovered with a perforated plate and placed into a humidity ovenmaintained at 30° C. with a relative humidity level (RH) of 95%.

After 48 hours in the humidity oven, the vials were removed from thehumidity oven, and visual viscosity observations were recorded using thesame method as in example 2. Results are below in Table 5.

TABLE 5 Ligand: 48 Hr. Ligand Ligand Metal Complexation ComplexationVisual No. μmoles Ratio Temp (deg C.) Time (min) Appearance Viscosity 36 2 75 45 clear 2

The examples show that the catalysts described above for ingredient (A)and tested as described herein are capable of catalyzing condensationreaction. The composition described herein may be free of tin catalysts,such as those described above. Without wishing to be bound by theory, itis thought that the catalysts described herein as ingredient (A) mayprovide alternative, comparable, or better cure performance in somecondensation reaction curable compositions, as compared to the samecomposition containing a tin catalyst.

1. A composition comprising ingredients (A) and (B): where Ingredient (A) is a catalytically effective amount of a reaction product of a Zn precursor and a ligand, where the Zn precursor is distinct from a reaction product of the Zn precursor and the ligand, and where the ligand is selected from the group consisting of Ligands (a), (b), (c), and (d), where Ligand (a) has general formula (ii)

where a bond with ‘Rn’ in the formula represents a covalent single bond or an aromatic bond forming part of a ring structure, Q¹ is a heteroatom selected from O and S, each A² and each A³ is independently selected from a hydrogen atom and a monovalent hydrocarbon group, each of A⁵ and A⁶ is independently selected from a hydrogen atom and a monovalent organic group, with the proviso that A⁵ and A⁶ may be bonded together to form a ring structure, each of A⁴ and A⁷ is independently selected from nothing, a hydrogen atom, and a monovalent organic group, A¹ is either a monovalent hydrocarbon group or a divalent linking group, with the proviso that when A¹ is a divalent linking group, then A¹ links the structure of general formula (ii) with a structure of formula (iii):

where * denotes a point of attachment, and Q¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are as defined above; Ligand (b) is

Ligand (c) is

and Ligand (d) is

and Ingredient (B) is a silicon containing base polymer having an average, per molecule, of one or more hydrolyzable substituents, and Ingredient (A) is capable of catalyzing a condensation reaction of the hydrolyzable substituents on ingredient (B).
 2. The composition of claim 1, where the condensation reaction produces a reaction product having a visual viscosity value ranging from 2 to 5 when tested according to the method of Example
 2. 3. A composition comprising: (A) a catalytically effective amount of a catalytically active reaction product of a reaction of ingredients i) and ii), where Ingredient i) is a Zn precursor of general formula Zn-A₂, where each A is independently a monovalent organic group; and Ingredient ii) is a ligand selected from the group consisting of ligands (b)-(d), where ligand (a) has general formula (ii)

where a bond with ‘Rn’ in the formula represents a covalent single bond or an aromatic bond forming part of a ring structure, Q¹ is a heteroatom selected from O and S, each A² and each A³ is independently selected from a hydrogen atom and a monovalent hydrocarbon group, each of A⁴, A⁵, A⁶, and A⁷ is independently selected from a hydrogen atom and a monovalent organic group, with the proviso that A⁵ and A⁶ may be bonded together to form a ring structure, A¹ is either a monovalent hydrocarbon group or a divalent linking group, with the proviso that when A¹ is a divalent linking group, then A¹ links the structure of general formula (ii) with a structure of formula (iii):

where * denotes a point of attachment, and Q¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are as defined above; Ligand (b) is

ligand (c) is

and ligand (d) is

and (B) a silicon containing base polymer having an average, per molecule, of one or more hydrolyzable substituents, where the composition is capable of reacting via condensation reaction.
 4. The composition of claim 3, where one of conditions (a) to (d) is met, where Condition (a) is that each A is a carboxylic ester group; or Condition (b) is that each A is octanoate; or Condition (c) is that each A is an aryl group; or Condition (d) is that each A is phenyl.
 5. The composition of claim 1, further comprising at least one additional ingredient distinct from ingredients (A) and (B), where the at least one additional ingredient is selected from the group consisting of: (C) a crosslinker; (D) a drying agent; (E) an extender, a plasticizer, or a combination thereof; (F) a filler; (G) a treating agent; (H) a biocide; (J) a flame retardant; (K) a surface modifier; (L) a chain lengthener; (M) an endblocker; (N) a nonreactive binder; (O) an anti-aging additive; (P) a water release agent; (Q) a pigment; (R) a rheological additive; (S) a vehicle; (T) a tackifying agent; (U) a corrosion inhibitor; and a combination thereof.
 6. A method for making the composition of claim 1 comprising: mixing ingredients comprising ingredient (A) and ingredient (B) so as to make the composition.
 7. A method comprising: exposing the composition of claim 1 to moisture to prepare a reaction product.
 8. A reaction product prepared by the method of claim 7, where the reaction product has a form selected from a gum, a gel, a rubber, and a resin; or where the reaction product has a form selected from a gum, a gel, a rubber, and a resin and the reaction product is clear and/or colorless.
 9. A method comprising: reacting i) a Zn precursor of general formula Zn-A₂, where each A is independently a monovalent organic group; or each A is a carboxylic ester group; or each A is octanoate; or each A is an aryl group; or each A is phenyl; and ii) ligand selected from the group consisting of ligands (a), (b), and (c), where ligand (a) has general formula (ii)

where a bond with ‘Rn’ in the formula represents a covalent single bond or an aromatic bond forming part of a ring structure, Q¹ is a heteroatom selected from O and S, each A² and each A³ is independently selected from a hydrogen atom and a monovalent hydrocarbon group, each of A⁴, A⁵, A⁶, and A⁷ is independently selected from a hydrogen atom and a monovalent organic group, with the proviso that A⁵ and A⁶ may be bonded together to form a ring structure, A¹ is either a monovalent hydrocarbon group or a divalent linking group, with the proviso that when A¹ is a divalent linking group, then A¹ links the structure of general formula (ii) with a structure of formula (iii):

where * denotes a point of attachment, and Q¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are as defined above; ligand (b) is

and ligand (c) is

thereby making a reaction product.
 10. The method of claim 9, further comprising heating the Zn precursor and the ligand.
 11. The method of claim 9, further comprising removing a by-product from the reaction product to yield the Zn-ligand complex free of the by-product.
 12. A reaction product prepared by the method of claim
 10. 13. The reaction product of claim 10, where the reaction product comprises: a) a Zn-ligand complex, and b) a by-product from the reaction of the Zn precursor and the ligand, or from a side reaction therein.
 14. A reaction product prepared by the method of claim
 11. 